public class BigDecimal extends Numberimplements Comparable <BigDecimal >
BigDecimal consists of an arbitrary precision integer
unscaled value and a 32-bit integer
scale. If zero or positive, the scale is the number of digits to the right of the decimal point. If negative, the unscaled value of the number is multiplied by ten to the power of the negation of the scale. The value of the number represented by the
BigDecimal is therefore
(unscaledValue × 10-scale).
The BigDecimal class provides operations for arithmetic, scale manipulation, rounding, comparison, hashing, and format conversion. The toString() method provides a canonical representation of a BigDecimal.
The BigDecimal class gives its user complete control over rounding behavior. If no rounding mode is specified and the exact result cannot be represented, an exception is thrown; otherwise, calculations can be carried out to a chosen precision and rounding mode by supplying an appropriate MathContext object to the operation. In either case, eight rounding modes are provided for the control of rounding. Using the integer fields in this class (such as ROUND_HALF_UP) to represent rounding mode is largely obsolete; the enumeration values of the RoundingMode enum, (such as RoundingMode) should be used instead.
When a MathContext object is supplied with a precision setting of 0 (for example, MathContext), arithmetic operations are exact, as are the arithmetic methods which take no MathContext object. (This is the only behavior that was supported in releases prior to 5.) As a corollary of computing the exact result, the rounding mode setting of a MathContext object with a precision setting of 0 is not used and thus irrelevant. In the case of divide, the exact quotient could have an infinitely long decimal expansion; for example, 1 divided by 3. If the quotient has a nonterminating decimal expansion and the operation is specified to return an exact result, an ArithmeticException is thrown. Otherwise, the exact result of the division is returned, as done for other operations.
When the precision setting is not 0, the rules of BigDecimal arithmetic are broadly compatible with selected modes of operation of the arithmetic defined in ANSI X3.274-1996 and ANSI X3.274-1996/AM 1-2000 (section 7.4). Unlike those standards, BigDecimal includes many rounding modes, which were mandatory for division in BigDecimal releases prior to 5. Any conflicts between these ANSI standards and the BigDecimal specification are resolved in favor of BigDecimal.
Since the same numerical value can have different representations (with different scales), the rules of arithmetic and rounding must specify both the numerical result and the scale used in the result's representation.
In general the rounding modes and precision setting determine how operations return results with a limited number of digits when the exact result has more digits (perhaps infinitely many in the case of division) than the number of digits returned. First, the total number of digits to return is specified by the MathContext's precision setting; this determines the result's precision. The digit count starts from the leftmost nonzero digit of the exact result. The rounding mode determines how any discarded trailing digits affect the returned result.
For all arithmetic operators , the operation is carried out as though an exact intermediate result were first calculated and then rounded to the number of digits specified by the precision setting (if necessary), using the selected rounding mode. If the exact result is not returned, some digit positions of the exact result are discarded. When rounding increases the magnitude of the returned result, it is possible for a new digit position to be created by a carry propagating to a leading "9" digit. For example, rounding the value 999.9 to three digits rounding up would be numerically equal to one thousand, represented as 100×101. In such cases, the new "1" is the leading digit position of the returned result.
Besides a logical exact result, each arithmetic operation has a preferred scale for representing a result. The preferred scale for each operation is listed in the table below.
| Operation | Preferred Scale of Result |
|---|---|
| Add | max(addend.scale(), augend.scale()) |
| Subtract | max(minuend.scale(), subtrahend.scale()) |
| Multiply | multiplier.scale() + multiplicand.scale() |
| Divide | dividend.scale() - divisor.scale() |
1/32 is
0.03125.
Before rounding, the scale of the logical exact intermediate result is the preferred scale for that operation. If the exact numerical result cannot be represented in precision digits, rounding selects the set of digits to return and the scale of the result is reduced from the scale of the intermediate result to the least scale which can represent the precision digits actually returned. If the exact result can be represented with at most precision digits, the representation of the result with the scale closest to the preferred scale is returned. In particular, an exactly representable quotient may be represented in fewer than precision digits by removing trailing zeros and decreasing the scale. For example, rounding to three digits using the floor rounding mode,
19/100 = 0.19 // integer=19, scale=2
but
21/110 = 0.190 // integer=190, scale=3
Note that for add, subtract, and multiply, the reduction in scale will equal the number of digit positions of the exact result which are discarded. If the rounding causes a carry propagation to create a new high-order digit position, an additional digit of the result is discarded than when no new digit position is created.
Other methods may have slightly different rounding semantics. For example, the result of the pow method using the specified algorithm can occasionally differ from the rounded mathematical result by more than one unit in the last place, one ulp.
Two types of operations are provided for manipulating the scale of a BigDecimal: scaling/rounding operations and decimal point motion operations. Scaling/rounding operations (setScale and round) return a BigDecimal whose value is approximately (or exactly) equal to that of the operand, but whose scale or precision is the specified value; that is, they increase or decrease the precision of the stored number with minimal effect on its value. Decimal point motion operations (movePointLeft and movePointRight) return a BigDecimal created from the operand by moving the decimal point a specified distance in the specified direction.
For the sake of brevity and clarity, pseudo-code is used throughout the descriptions of BigDecimal methods. The pseudo-code expression (i + j) is shorthand for "a BigDecimal whose value is that of the BigDecimal i added to that of the BigDecimal j." The pseudo-code expression (i == j) is shorthand for "true if and only if the BigDecimal i represents the same value as the BigDecimal j." Other pseudo-code expressions are interpreted similarly. Square brackets are used to represent the particular BigInteger and scale pair defining a BigDecimal value; for example [19, 2] is the BigDecimal numerically equal to 0.19 having a scale of 2.
Note: care should be exercised if BigDecimal objects are used as keys in a SortedMap or elements in a SortedSet since BigDecimal's natural ordering is inconsistent with equals. See Comparable, SortedMap or SortedSet for more information.
All methods and constructors for this class throw NullPointerException when passed a null object reference for any input parameter.
BigInteger,
MathContext,
RoundingMode,
SortedMap,
SortedSet,
Serialized Form
| Modifier and Type | Field and Description |
|---|---|
static BigDecimal |
ONE
The value 1, with a scale of 0.
|
static int |
ROUND_CEILING
Rounding mode to round towards positive infinity.
|
static int |
ROUND_DOWN
Rounding mode to round towards zero.
|
static int |
ROUND_FLOOR
Rounding mode to round towards negative infinity.
|
static int |
ROUND_HALF_DOWN
Rounding mode to round towards "nearest neighbor" unless both neighbors are equidistant, in which case round down.
|
static int |
ROUND_HALF_EVEN
Rounding mode to round towards the "nearest neighbor" unless both neighbors are equidistant, in which case, round towards the even neighbor.
|
static int |
ROUND_HALF_UP
Rounding mode to round towards "nearest neighbor" unless both neighbors are equidistant, in which case round up.
|
static int |
ROUND_UNNECESSARY
Rounding mode to assert that the requested operation has an exact result, hence no rounding is necessary.
|
static int |
ROUND_UP
Rounding mode to round away from zero.
|
static BigDecimal |
TEN
The value 10, with a scale of 0.
|
static BigDecimal |
ZERO
The value 0, with a scale of 0.
|
| Constructor and Description |
|---|
BigDecimal(BigInteger
Translates a
BigInteger into a
BigDecimal.
|
BigDecimal(BigInteger
Translates a
BigInteger unscaled value and an
int scale into a
BigDecimal.
|
BigDecimal(BigInteger
Translates a
BigInteger unscaled value and an
int scale into a
BigDecimal, with rounding according to the context settings.
|
BigDecimal(BigInteger
Translates a
BigInteger into a
BigDecimal rounding according to the context settings.
|
BigDecimal(char[] in)
Translates a character array representation of a
BigDecimal into a
BigDecimal, accepting the same sequence of characters as the
BigDecimal(String) constructor.
|
BigDecimal(char[] in, int offset, int len)
Translates a character array representation of a
BigDecimal into a
BigDecimal, accepting the same sequence of characters as the
BigDecimal(String) constructor, while allowing a sub-array to be specified.
|
BigDecimal(char[] in, int offset, int len, MathContext
Translates a character array representation of a
BigDecimal into a
BigDecimal, accepting the same sequence of characters as the
BigDecimal(String) constructor, while allowing a sub-array to be specified and with rounding according to the context settings.
|
BigDecimal(char[] in, MathContext
Translates a character array representation of a
BigDecimal into a
BigDecimal, accepting the same sequence of characters as the
BigDecimal(String) constructor and with rounding according to the context settings.
|
BigDecimal(double val)
Translates a
double into a
BigDecimal which is the exact decimal representation of the
double's binary floating-point value.
|
BigDecimal(double val, MathContext
Translates a
double into a
BigDecimal, with rounding according to the context settings.
|
BigDecimal(int val)
Translates an
int into a
BigDecimal.
|
BigDecimal(int val, MathContext
Translates an
int into a
BigDecimal, with rounding according to the context settings.
|
BigDecimal(long val)
Translates a
long into a
BigDecimal.
|
BigDecimal(long val, MathContext
Translates a
long into a
BigDecimal, with rounding according to the context settings.
|
BigDecimal(String
Translates the string representation of a
BigDecimal into a
BigDecimal.
|
BigDecimal(String
Translates the string representation of a
BigDecimal into a
BigDecimal, accepting the same strings as the
BigDecimal(String) constructor, with rounding according to the context settings.
|
| Modifier and Type | Method and Description |
|---|---|
BigDecimal |
abs()
Returns a
BigDecimal whose value is the absolute value of this
BigDecimal, and whose scale is
this.scale().
|
BigDecimal |
abs(MathContext
Returns a
BigDecimal whose value is the absolute value of this
BigDecimal, with rounding according to the context settings.
|
BigDecimal |
add(BigDecimal
Returns a
BigDecimal whose value is
(this + augend), and whose scale is
max(this.scale(), augend.scale()).
|
BigDecimal |
add(BigDecimal
Returns a
BigDecimal whose value is
(this + augend), with rounding according to the context settings.
|
byte |
byteValueExact()
Converts this
BigDecimal to a
byte, checking for lost information.
|
int |
compareTo(BigDecimal
Compares this
BigDecimal with the specified
BigDecimal.
|
BigDecimal |
divide(BigDecimal
Returns a
BigDecimal whose value is
(this / divisor), and whose preferred scale is
(this.scale() - divisor.scale()); if the exact quotient cannot be represented (because it has a non-terminating decimal expansion) an
ArithmeticException is thrown.
|
BigDecimal |
divide(BigDecimal
Returns a
BigDecimal whose value is
(this / divisor), and whose scale is
this.scale().
|
BigDecimal |
divide(BigDecimal
Returns a
BigDecimal whose value is
(this / divisor), and whose scale is as specified.
|
BigDecimal |
divide(BigDecimal
Returns a
BigDecimal whose value is
(this / divisor), and whose scale is as specified.
|
BigDecimal |
divide(BigDecimal
Returns a
BigDecimal whose value is
(this / divisor), with rounding according to the context settings.
|
BigDecimal |
divide(BigDecimal
Returns a
BigDecimal whose value is
(this / divisor), and whose scale is
this.scale().
|
BigDecimal |
divideAndRemainder(BigDecimal
Returns a two-element
BigDecimal array containing the result of
divideToIntegralValue followed by the result of
remainder on the two operands.
|
BigDecimal |
divideAndRemainder(BigDecimal
Returns a two-element
BigDecimal array containing the result of
divideToIntegralValue followed by the result of
remainder on the two operands calculated with rounding according to the context settings.
|
BigDecimal |
divideToIntegralValue(BigDecimal
Returns a
BigDecimal whose value is the integer part of the quotient
(this / divisor) rounded down.
|
BigDecimal |
divideToIntegralValue(BigDecimal
Returns a
BigDecimal whose value is the integer part of
(this / divisor).
|
double |
doubleValue()
Converts this
BigDecimal to a
double.
|
boolean |
equals(Object
Compares this
BigDecimal with the specified
Object for equality.
|
float |
floatValue()
Converts this
BigDecimal to a
float.
|
int |
hashCode()
Returns the hash code for this
BigDecimal.
|
int |
intValue()
Converts this
BigDecimal to an
int.
|
int |
intValueExact()
Converts this
BigDecimal to an
int, checking for lost information.
|
long |
longValue()
Converts this
BigDecimal to a
long.
|
long |
longValueExact()
Converts this
BigDecimal to a
long, checking for lost information.
|
BigDecimal |
max(BigDecimal
Returns the maximum of this
BigDecimal and
val.
|
BigDecimal |
min(BigDecimal
Returns the minimum of this
BigDecimal and
val.
|
BigDecimal |
movePointLeft(int n)
Returns a
BigDecimal which is equivalent to this one with the decimal point moved
n places to the left.
|
BigDecimal |
movePointRight(int n)
Returns a
BigDecimal which is equivalent to this one with the decimal point moved
n places to the right.
|
BigDecimal |
multiply(BigDecimal
Returns a
BigDecimal whose value is
(this × multiplicand), and whose scale is
(this.scale() + multiplicand.scale()).
|
BigDecimal |
multiply(BigDecimal
Returns a
BigDecimal whose value is
(this × multiplicand), with rounding according to the context settings.
|
BigDecimal |
negate()
Returns a
BigDecimal whose value is
(-this), and whose scale is
this.scale().
|
BigDecimal |
negate(MathContext
Returns a
BigDecimal whose value is
(-this), with rounding according to the context settings.
|
BigDecimal |
plus()
Returns a
BigDecimal whose value is
(+this), and whose scale is
this.scale().
|
BigDecimal |
plus(MathContext
Returns a
BigDecimal whose value is
(+this), with rounding according to the context settings.
|
BigDecimal |
pow(int n)
Returns a
BigDecimal whose value is
(thisn), The power is computed exactly, to unlimited precision.
|
BigDecimal |
pow(int n, MathContext
Returns a
BigDecimal whose value is
(thisn).
|
int |
precision()
Returns the
precision of this
BigDecimal.
|
BigDecimal |
remainder(BigDecimal
Returns a
BigDecimal whose value is
(this % divisor).
|
BigDecimal |
remainder(BigDecimal
Returns a
BigDecimal whose value is
(this % divisor), with rounding according to the context settings.
|
BigDecimal |
round(MathContext
Returns a
BigDecimal rounded according to the
MathContext settings.
|
int |
scale()
Returns the
scale of this
BigDecimal.
|
BigDecimal |
scaleByPowerOfTen(int n)
Returns a BigDecimal whose numerical value is equal to (
this * 10
n).
|
BigDecimal |
setScale(int newScale)
Returns a
BigDecimal whose scale is the specified value, and whose value is numerically equal to this
BigDecimal's.
|
BigDecimal |
setScale(int newScale, int roundingMode)
Returns a
BigDecimal whose scale is the specified value, and whose unscaled value is determined by multiplying or dividing this
BigDecimal's unscaled value by the appropriate power of ten to maintain its overall value.
|
BigDecimal |
setScale(int newScale, RoundingMode
Returns a
BigDecimal whose scale is the specified value, and whose unscaled value is determined by multiplying or dividing this
BigDecimal's unscaled value by the appropriate power of ten to maintain its overall value.
|
short |
shortValueExact()
Converts this
BigDecimal to a
short, checking for lost information.
|
int |
signum()
Returns the signum function of this
BigDecimal.
|
BigDecimal |
stripTrailingZeros()
Returns a
BigDecimal which is numerically equal to this one but with any trailing zeros removed from the representation.
|
BigDecimal |
subtract(BigDecimal
Returns a
BigDecimal whose value is
(this - subtrahend), and whose scale is
max(this.scale(), subtrahend.scale()).
|
BigDecimal |
subtract(BigDecimal
Returns a
BigDecimal whose value is
(this - subtrahend), with rounding according to the context settings.
|
BigInteger |
toBigInteger()
Converts this
BigDecimal to a
BigInteger.
|
BigInteger |
toBigIntegerExact()
Converts this
BigDecimal to a
BigInteger, checking for lost information.
|
String |
toEngineeringString()
Returns a string representation of this
BigDecimal, using engineering notation if an exponent is needed.
|
String |
toPlainString()
Returns a string representation of this
BigDecimal without an exponent field.
|
String |
toString()
Returns the string representation of this
BigDecimal, using scientific notation if an exponent is needed.
|
BigDecimal |
ulp()
Returns the size of an ulp, a unit in the last place, of this
BigDecimal.
|
BigInteger |
unscaledValue()
Returns a
BigInteger whose value is the
unscaled value of this
BigDecimal.
|
static BigDecimal |
valueOf(double val)
Translates a
double into a
BigDecimal, using the
double's canonical string representation provided by the
Double method.
|
static BigDecimal |
valueOf(long val)
Translates a
long value into a
BigDecimal with a scale of zero.
|
static BigDecimal |
valueOf(long unscaledVal, int scale)
Translates a
long unscaled value and an
int scale into a
BigDecimal.
|
byteValue, shortValuepublic static final BigDecimalZERO
public static final BigDecimalONE
public static final BigDecimalTEN
public static final int ROUND_UP
public static final int ROUND_DOWN
public static final int ROUND_CEILING
BigDecimal is positive, behaves as for
ROUND_UP; if negative, behaves as for
ROUND_DOWN. Note that this rounding mode never decreases the calculated value.
public static final int ROUND_FLOOR
BigDecimal is positive, behave as for
ROUND_DOWN; if negative, behave as for
ROUND_UP. Note that this rounding mode never increases the calculated value.
public static final int ROUND_HALF_UP
ROUND_UP if the discarded fraction is ≥ 0.5; otherwise, behaves as for
ROUND_DOWN. Note that this is the rounding mode that most of us were taught in grade school.
public static final int ROUND_HALF_DOWN
ROUND_UP if the discarded fraction is > 0.5; otherwise, behaves as for
ROUND_DOWN.
public static final int ROUND_HALF_EVEN
ROUND_HALF_UP if the digit to the left of the discarded fraction is odd; behaves as for
ROUND_HALF_DOWN if it's even. Note that this is the rounding mode that minimizes cumulative error when applied repeatedly over a sequence of calculations.
public static final int ROUND_UNNECESSARY
ArithmeticException is thrown.
public BigDecimal(char[] in,
int offset,
int len)
BigDecimal into a
BigDecimal, accepting the same sequence of characters as the
BigDecimal(String) constructor, while allowing a sub-array to be specified.
Note that if the sequence of characters is already available within a character array, using this constructor is faster than converting the char array to string and using the BigDecimal(String) constructor .
in -
char array that is the source of characters.
offset - first character in the array to inspect.
len - number of characters to consider.
NumberFormatException - if
in is not a valid representation of a
BigDecimal or the defined subarray is not wholly within
in.
public BigDecimal(char[] in,
int offset,
int len,
MathContext mc)
BigDecimal into a
BigDecimal, accepting the same sequence of characters as the
BigDecimal(String) constructor, while allowing a sub-array to be specified and with rounding according to the context settings.
Note that if the sequence of characters is already available within a character array, using this constructor is faster than converting the char array to string and using the BigDecimal(String) constructor .
in -
char array that is the source of characters.
offset - first character in the array to inspect.
len - number of characters to consider..
mc - the context to use.
ArithmeticException - if the result is inexact but the rounding mode is
UNNECESSARY.
NumberFormatException - if
in is not a valid representation of a
BigDecimal or the defined subarray is not wholly within
in.
public BigDecimal(char[] in)
BigDecimal into a
BigDecimal, accepting the same sequence of characters as the
BigDecimal(String) constructor.
Note that if the sequence of characters is already available as a character array, using this constructor is faster than converting the char array to string and using the BigDecimal(String) constructor .
in -
char array that is the source of characters.
NumberFormatException - if
in is not a valid representation of a
BigDecimal.
public BigDecimal(char[] in,
MathContext mc)
BigDecimal into a
BigDecimal, accepting the same sequence of characters as the
BigDecimal(String) constructor and with rounding according to the context settings.
Note that if the sequence of characters is already available as a character array, using this constructor is faster than converting the char array to string and using the BigDecimal(String) constructor .
in -
char array that is the source of characters.
mc - the context to use.
ArithmeticException - if the result is inexact but the rounding mode is
UNNECESSARY.
NumberFormatException - if
in is not a valid representation of a
BigDecimal.
public BigDecimal(Stringval)
BigDecimal into a
BigDecimal. The string representation consists of an optional sign,
'+' (
'\u002B') or
'-' (
'\u002D'), followed by a sequence of zero or more decimal digits ("the integer"), optionally followed by a fraction, optionally followed by an exponent.
The fraction consists of a decimal point followed by zero or more decimal digits. The string must contain at least one digit in either the integer or the fraction. The number formed by the sign, the integer and the fraction is referred to as the significand.
The exponent consists of the character 'e' ('\u0065') or 'E' ('\u0045') followed by one or more decimal digits. The value of the exponent must lie between -Integer (Integer+1) and Integer, inclusive.
More formally, the strings this constructor accepts are described by the following grammar:
- BigDecimalString:
- Signopt Significand Exponentopt
- Sign:
+-- Significand:
- IntegerPart
.FractionPartopt.FractionPart- IntegerPart
- IntegerPart:
- Digits
- FractionPart:
- Digits
- Exponent:
- ExponentIndicator SignedInteger
- ExponentIndicator:
eE- SignedInteger:
- Signopt Digits
- Digits:
- Digit
- Digits Digit
- Digit:
- any character for which
Characterreturns.isDigit(char) true, including 0, 1, 2 ...
The scale of the returned BigDecimal will be the number of digits in the fraction, or zero if the string contains no decimal point, subject to adjustment for any exponent; if the string contains an exponent, the exponent is subtracted from the scale. The value of the resulting scale must lie between Integer.MIN_VALUE and Integer.MAX_VALUE, inclusive.
The character-to-digit mapping is provided by Character set to convert to radix 10. The String may not contain any extraneous characters (whitespace, for example).
Examples:
The value of the returned BigDecimal is equal to significand × 10 exponent. For each string on the left, the resulting representation [BigInteger, scale] is shown on the right.
"0" [0,0] "0.00" [0,2] "123" [123,0] "-123" [-123,0] "1.23E3" [123,-1] "1.23E+3" [123,-1] "12.3E+7" [123,-6] "12.0" [120,1] "12.3" [123,1] "0.00123" [123,5] "-1.23E-12" [-123,14] "1234.5E-4" [12345,5] "0E+7" [0,-7] "-0" [0,0]
Note: For values other than float and double NaN and ±Infinity, this constructor is compatible with the values returned by Float and Double. This is generally the preferred way to convert a float or double into a BigDecimal, as it doesn't suffer from the unpredictability of the BigDecimal(double) constructor.
val - String representation of
BigDecimal.
NumberFormatException - if
val is not a valid representation of a
BigDecimal.
public BigDecimal(Stringval, MathContext mc)
BigDecimal into a
BigDecimal, accepting the same strings as the
BigDecimal(String) constructor, with rounding according to the context settings.
val - string representation of a
BigDecimal.
mc - the context to use.
ArithmeticException - if the result is inexact but the rounding mode is
UNNECESSARY.
NumberFormatException - if
val is not a valid representation of a BigDecimal.
public BigDecimal(double val)
double into a
BigDecimal which is the exact decimal representation of the
double's binary floating-point value. The scale of the returned
BigDecimal is the smallest value such that
(10scale × val) is an integer.
Notes:
new BigDecimal(0.1) in Java creates a BigDecimal which is exactly equal to 0.1 (an unscaled value of 1, with a scale of 1), but it is actually equal to 0.1000000000000000055511151231257827021181583404541015625. This is because 0.1 cannot be represented exactly as a double (or, for that matter, as a binary fraction of any finite length). Thus, the value that is being passed in to the constructor is not exactly equal to 0.1, appearances notwithstanding. String constructor, on the other hand, is perfectly predictable: writing new BigDecimal("0.1") creates a BigDecimal which is exactly equal to 0.1, as one would expect. Therefore, it is generally recommended that the String constructor be used in preference to this one. double must be used as a source for a BigDecimal, note that this constructor provides an exact conversion; it does not give the same result as converting the double to a String using the Double.toString(double) method and then using the BigDecimal(String) constructor. To get that result, use the static valueOf(double) method. val -
double value to be converted to
BigDecimal.
NumberFormatException - if
val is infinite or NaN.
public BigDecimal(double val,
MathContext mc)
double into a
BigDecimal, with rounding according to the context settings. The scale of the
BigDecimal is the smallest value such that
(10scale × val) is an integer.
The results of this constructor can be somewhat unpredictable and its use is generally not recommended; see the notes under the BigDecimal(double) constructor.
val -
double value to be converted to
BigDecimal.
mc - the context to use.
ArithmeticException - if the result is inexact but the RoundingMode is UNNECESSARY.
NumberFormatException - if
val is infinite or NaN.
public BigDecimal(BigIntegerval)
BigInteger into a
BigDecimal. The scale of the
BigDecimal is zero.
val -
BigInteger value to be converted to
BigDecimal.
public BigDecimal(BigIntegerval, MathContext mc)
BigInteger into a
BigDecimal rounding according to the context settings. The scale of the
BigDecimal is zero.
val -
BigInteger value to be converted to
BigDecimal.
mc - the context to use.
ArithmeticException - if the result is inexact but the rounding mode is
UNNECESSARY.
public BigDecimal(BigIntegerunscaledVal, int scale)
BigInteger unscaled value and an
int scale into a
BigDecimal. The value of the
BigDecimal is
(unscaledVal × 10-scale).
unscaledVal - unscaled value of the
BigDecimal.
scale - scale of the
BigDecimal.
public BigDecimal(BigIntegerunscaledVal, int scale, MathContext mc)
BigInteger unscaled value and an
int scale into a
BigDecimal, with rounding according to the context settings. The value of the
BigDecimal is
(unscaledVal × 10-scale), rounded according to the
precision and rounding mode settings.
unscaledVal - unscaled value of the
BigDecimal.
scale - scale of the
BigDecimal.
mc - the context to use.
ArithmeticException - if the result is inexact but the rounding mode is
UNNECESSARY.
public BigDecimal(int val)
int into a
BigDecimal. The scale of the
BigDecimal is zero.
val -
int value to be converted to
BigDecimal.
public BigDecimal(int val,
MathContext mc)
int into a
BigDecimal, with rounding according to the context settings. The scale of the
BigDecimal, before any rounding, is zero.
val -
int value to be converted to
BigDecimal.
mc - the context to use.
ArithmeticException - if the result is inexact but the rounding mode is
UNNECESSARY.
public BigDecimal(long val)
long into a
BigDecimal. The scale of the
BigDecimal is zero.
val -
long value to be converted to
BigDecimal.
public BigDecimal(long val,
MathContext mc)
long into a
BigDecimal, with rounding according to the context settings. The scale of the
BigDecimal, before any rounding, is zero.
val -
long value to be converted to
BigDecimal.
mc - the context to use.
ArithmeticException - if the result is inexact but the rounding mode is
UNNECESSARY.
public static BigDecimalvalueOf(long unscaledVal, int scale)
long unscaled value and an
int scale into a
BigDecimal. This "static factory method" is provided in preference to a (
long,
int) constructor because it allows for reuse of frequently used
BigDecimal values..
unscaledVal - unscaled value of the
BigDecimal.
scale - scale of the
BigDecimal.
BigDecimal whose value is
(unscaledVal × 10-scale).
public static BigDecimalvalueOf(long val)
long value into a
BigDecimal with a scale of zero. This "static factory method" is provided in preference to a (
long) constructor because it allows for reuse of frequently used
BigDecimal values.
val - value of the
BigDecimal.
BigDecimal whose value is
val.
public static BigDecimalvalueOf(double val)
double into a
BigDecimal, using the
double's canonical string representation provided by the
Double.toString(double) method.
Note: This is generally the preferred way to convert a double (or float) into a BigDecimal, as the value returned is equal to that resulting from constructing a BigDecimal from the result of using Double.
val -
double to convert to a
BigDecimal.
BigDecimal whose value is equal to or approximately equal to the value of
val.
NumberFormatException - if
val is infinite or NaN.
public BigDecimaladd(BigDecimal augend)
BigDecimal whose value is
(this + augend), and whose scale is
max(this.scale(), augend.scale()).
augend - value to be added to this
BigDecimal.
this + augend
public BigDecimaladd(BigDecimal augend, MathContext mc)
BigDecimal whose value is
(this + augend), with rounding according to the context settings. If either number is zero and the precision setting is nonzero then the other number, rounded if necessary, is used as the result.
augend - value to be added to this
BigDecimal.
mc - the context to use.
this + augend, rounded as necessary.
ArithmeticException - if the result is inexact but the rounding mode is
UNNECESSARY.
public BigDecimalsubtract(BigDecimal subtrahend)
BigDecimal whose value is
(this - subtrahend), and whose scale is
max(this.scale(), subtrahend.scale()).
subtrahend - value to be subtracted from this
BigDecimal.
this - subtrahend
public BigDecimalsubtract(BigDecimal subtrahend, MathContext mc)
BigDecimal whose value is
(this - subtrahend), with rounding according to the context settings. If
subtrahend is zero then this, rounded if necessary, is used as the result. If this is zero then the result is
subtrahend.negate(mc).
subtrahend - value to be subtracted from this
BigDecimal.
mc - the context to use.
this - subtrahend, rounded as necessary.
ArithmeticException - if the result is inexact but the rounding mode is
UNNECESSARY.
public BigDecimalmultiply(BigDecimal multiplicand)
BigDecimal whose value is
(this × multiplicand), and whose scale is
(this.scale() + multiplicand.scale()).
multiplicand - value to be multiplied by this
BigDecimal.
this * multiplicand
public BigDecimalmultiply(BigDecimal multiplicand, MathContext mc)
BigDecimal whose value is
(this × multiplicand), with rounding according to the context settings.
multiplicand - value to be multiplied by this
BigDecimal.
mc - the context to use.
this * multiplicand, rounded as necessary.
ArithmeticException - if the result is inexact but the rounding mode is
UNNECESSARY.
public BigDecimaldivide(BigDecimal divisor, int scale, int roundingMode)
BigDecimal whose value is
(this / divisor), and whose scale is as specified. If rounding must be performed to generate a result with the specified scale, the specified rounding mode is applied.
The new divide(BigDecimal, int, RoundingMode) method should be used in preference to this legacy method.
divisor - value by which this
BigDecimal is to be divided.
scale - scale of the
BigDecimal quotient to be returned.
roundingMode - rounding mode to apply.
this / divisor
ArithmeticException - if
divisor is zero,
roundingMode==ROUND_UNNECESSARY and the specified scale is insufficient to represent the result of the division exactly.
IllegalArgumentException - if
roundingMode does not represent a valid rounding mode.
ROUND_UP,
ROUND_DOWN,
ROUND_CEILING,
ROUND_FLOOR,
ROUND_HALF_UP,
ROUND_HALF_DOWN,
ROUND_HALF_EVEN,
ROUND_UNNECESSARY
public BigDecimaldivide(BigDecimal divisor, int scale, RoundingMode roundingMode)
BigDecimal whose value is
(this / divisor), and whose scale is as specified. If rounding must be performed to generate a result with the specified scale, the specified rounding mode is applied.
divisor - value by which this
BigDecimal is to be divided.
scale - scale of the
BigDecimal quotient to be returned.
roundingMode - rounding mode to apply.
this / divisor
ArithmeticException - if
divisor is zero,
roundingMode==RoundingMode.UNNECESSARY and the specified scale is insufficient to represent the result of the division exactly.
public BigDecimaldivide(BigDecimal divisor, int roundingMode)
BigDecimal whose value is
(this / divisor), and whose scale is
this.scale(). If rounding must be performed to generate a result with the given scale, the specified rounding mode is applied.
The new divide(BigDecimal, RoundingMode) method should be used in preference to this legacy method.
divisor - value by which this
BigDecimal is to be divided.
roundingMode - rounding mode to apply.
this / divisor
ArithmeticException - if
divisor==0, or
roundingMode==ROUND_UNNECESSARY and
this.scale() is insufficient to represent the result of the division exactly.
IllegalArgumentException - if
roundingMode does not represent a valid rounding mode.
ROUND_UP,
ROUND_DOWN,
ROUND_CEILING,
ROUND_FLOOR,
ROUND_HALF_UP,
ROUND_HALF_DOWN,
ROUND_HALF_EVEN,
ROUND_UNNECESSARY
public BigDecimaldivide(BigDecimal divisor, RoundingMode roundingMode)
BigDecimal whose value is
(this / divisor), and whose scale is
this.scale(). If rounding must be performed to generate a result with the given scale, the specified rounding mode is applied.
divisor - value by which this
BigDecimal is to be divided.
roundingMode - rounding mode to apply.
this / divisor
ArithmeticException - if
divisor==0, or
roundingMode==RoundingMode.UNNECESSARY and
this.scale() is insufficient to represent the result of the division exactly.
public BigDecimaldivide(BigDecimal divisor)
BigDecimal whose value is
(this / divisor), and whose preferred scale is
(this.scale() - divisor.scale()); if the exact quotient cannot be represented (because it has a non-terminating decimal expansion) an
ArithmeticException is thrown.
divisor - value by which this
BigDecimal is to be divided.
this / divisor
ArithmeticException - if the exact quotient does not have a terminating decimal expansion
public BigDecimaldivide(BigDecimal divisor, MathContext mc)
BigDecimal whose value is
(this / divisor), with rounding according to the context settings.
divisor - value by which this
BigDecimal is to be divided.
mc - the context to use.
this / divisor, rounded as necessary.
ArithmeticException - if the result is inexact but the rounding mode is
UNNECESSARY or
mc.precision == 0 and the quotient has a non-terminating decimal expansion.
public BigDecimaldivideToIntegralValue(BigDecimal divisor)
BigDecimal whose value is the integer part of the quotient
(this / divisor) rounded down. The preferred scale of the result is
(this.scale() - divisor.scale()).
divisor - value by which this
BigDecimal is to be divided.
this / divisor.
ArithmeticException - if
divisor==0
public BigDecimaldivideToIntegralValue(BigDecimal divisor, MathContext mc)
BigDecimal whose value is the integer part of
(this / divisor). Since the integer part of the exact quotient does not depend on the rounding mode, the rounding mode does not affect the values returned by this method. The preferred scale of the result is
(this.scale() - divisor.scale()). An
ArithmeticException is thrown if the integer part of the exact quotient needs more than
mc.precision digits.
divisor - value by which this
BigDecimal is to be divided.
mc - the context to use.
this / divisor.
ArithmeticException - if
divisor==0
ArithmeticException - if
mc.precision > 0 and the result requires a precision of more than
mc.precision digits.
public BigDecimalremainder(BigDecimal divisor)
BigDecimal whose value is
(this % divisor).
The remainder is given by this.subtract(this.divideToIntegralValue(divisor).multiply(divisor)). Note that this is not the modulo operation (the result can be negative).
divisor - value by which this
BigDecimal is to be divided.
this % divisor.
ArithmeticException - if
divisor==0
public BigDecimalremainder(BigDecimal divisor, MathContext mc)
BigDecimal whose value is
(this % divisor), with rounding according to the context settings. The
MathContext settings affect the implicit divide used to compute the remainder. The remainder computation itself is by definition exact. Therefore, the remainder may contain more than
mc.getPrecision() digits.
The remainder is given by this.subtract(this.divideToIntegralValue(divisor, mc).multiply(divisor)). Note that this is not the modulo operation (the result can be negative).
divisor - value by which this
BigDecimal is to be divided.
mc - the context to use.
this % divisor, rounded as necessary.
ArithmeticException - if
divisor==0
ArithmeticException - if the result is inexact but the rounding mode is
UNNECESSARY, or
mc.precision > 0 and the result of
this.divideToIntgralValue(divisor) would require a precision of more than
mc.precision digits.
divideToIntegralValue(java.math.BigDecimal, java.math.MathContext)
public BigDecimal[] divideAndRemainder(BigDecimal divisor)
BigDecimal array containing the result of
divideToIntegralValue followed by the result of
remainder on the two operands.
Note that if both the integer quotient and remainder are needed, this method is faster than using the divideToIntegralValue and remainder methods separately because the division need only be carried out once.
divisor - value by which this
BigDecimal is to be divided, and the remainder computed.
BigDecimal array: the quotient (the result of
divideToIntegralValue) is the initial element and the remainder is the final element.
ArithmeticException - if
divisor==0
divideToIntegralValue(java.math.BigDecimal, java.math.MathContext),
remainder(java.math.BigDecimal, java.math.MathContext)
public BigDecimal[] divideAndRemainder(BigDecimal divisor, MathContext mc)
BigDecimal array containing the result of
divideToIntegralValue followed by the result of
remainder on the two operands calculated with rounding according to the context settings.
Note that if both the integer quotient and remainder are needed, this method is faster than using the divideToIntegralValue and remainder methods separately because the division need only be carried out once.
divisor - value by which this
BigDecimal is to be divided, and the remainder computed.
mc - the context to use.
BigDecimal array: the quotient (the result of
divideToIntegralValue) is the initial element and the remainder is the final element.
ArithmeticException - if
divisor==0
ArithmeticException - if the result is inexact but the rounding mode is
UNNECESSARY, or
mc.precision > 0 and the result of
this.divideToIntgralValue(divisor) would require a precision of more than
mc.precision digits.
divideToIntegralValue(java.math.BigDecimal, java.math.MathContext),
remainder(java.math.BigDecimal, java.math.MathContext)
public BigDecimalpow(int n)
BigDecimal whose value is
(thisn), The power is computed exactly, to unlimited precision.
The parameter n must be in the range 0 through 999999999, inclusive. ZERO.pow(0) returns ONE. Note that future releases may expand the allowable exponent range of this method.
n - power to raise this
BigDecimal to.
ArithmeticException - if
n is out of range.
public BigDecimalpow(int n, MathContext mc)
BigDecimal whose value is
(thisn). The current implementation uses the core algorithm defined in ANSI standard X3.274-1996 with rounding according to the context settings. In general, the returned numerical value is within two ulps of the exact numerical value for the chosen precision. Note that future releases may use a different algorithm with a decreased allowable error bound and increased allowable exponent range.
The X3.274-1996 algorithm is:
ArithmeticException exception is thrown if
abs(n) > 999999999 mc.precision == 0 and n < 0 mc.precision > 0 and n has more than mc.precision decimal digits n is zero, ONE is returned even if this is zero, otherwise
n is positive, the result is calculated via the repeated squaring technique into a single accumulator. The individual multiplications with the accumulator use the same math context settings as in mc except for a precision increased to mc.precision + elength + 1 where elength is the number of decimal digits in n. n is negative, the result is calculated as if n were positive; this value is then divided into one using the working precision specified above. n - power to raise this
BigDecimal to.
mc - the context to use.
ArithmeticException - if the result is inexact but the rounding mode is
UNNECESSARY, or
n is out of range.
public BigDecimalabs()
BigDecimal whose value is the absolute value of this
BigDecimal, and whose scale is
this.scale().
abs(this)
public BigDecimalabs(MathContext mc)
BigDecimal whose value is the absolute value of this
BigDecimal, with rounding according to the context settings.
mc - the context to use.
abs(this), rounded as necessary.
ArithmeticException - if the result is inexact but the rounding mode is
UNNECESSARY.
public BigDecimalnegate()
BigDecimal whose value is
(-this), and whose scale is
this.scale().
-this.
public BigDecimalnegate(MathContext mc)
BigDecimal whose value is
(-this), with rounding according to the context settings.
mc - the context to use.
-this, rounded as necessary.
ArithmeticException - if the result is inexact but the rounding mode is
UNNECESSARY.
public BigDecimalplus()
BigDecimal whose value is
(+this), and whose scale is
this.scale().
This method, which simply returns this BigDecimal is included for symmetry with the unary minus method negate().
this.
negate()
public BigDecimalplus(MathContext mc)
BigDecimal whose value is
(+this), with rounding according to the context settings.
The effect of this method is identical to that of the round(MathContext) method.
mc - the context to use.
this, rounded as necessary. A zero result will have a scale of 0.
ArithmeticException - if the result is inexact but the rounding mode is
UNNECESSARY.
round(MathContext)
public int signum()
BigDecimal.
BigDecimal is negative, zero, or positive.
public int scale()
BigDecimal. If zero or positive, the scale is the number of digits to the right of the decimal point. If negative, the unscaled value of the number is multiplied by ten to the power of the negation of the scale. For example, a scale of
-3 means the unscaled value is multiplied by 1000.
BigDecimal.
public int precision()
BigDecimal. (The precision is the number of digits in the unscaled value.)
The precision of a zero value is 1.
BigDecimal.
public BigIntegerunscaledValue()
BigInteger whose value is the
unscaled value of this
BigDecimal. (Computes
(this * 10this.scale()).)
BigDecimal.
public BigDecimalround(MathContext mc)
BigDecimal rounded according to the
MathContext settings. If the precision setting is 0 then no rounding takes place.
The effect of this method is identical to that of the plus(MathContext) method.
mc - the context to use.
BigDecimal rounded according to the
MathContext settings.
ArithmeticException - if the rounding mode is
UNNECESSARY and the
BigDecimal operation would require rounding.
plus(MathContext)
public BigDecimalsetScale(int newScale, RoundingMode roundingMode)
BigDecimal whose scale is the specified value, and whose unscaled value is determined by multiplying or dividing this
BigDecimal's unscaled value by the appropriate power of ten to maintain its overall value. If the scale is reduced by the operation, the unscaled value must be divided (rather than multiplied), and the value may be changed; in this case, the specified rounding mode is applied to the division.
Note that since BigDecimal objects are immutable, calls of this method do not result in the original object being modified, contrary to the usual convention of having methods named setX mutate field X. Instead, setScale returns an object with the proper scale; the returned object may or may not be newly allocated.
newScale - scale of the
BigDecimal value to be returned.
roundingMode - The rounding mode to apply.
BigDecimal whose scale is the specified value, and whose unscaled value is determined by multiplying or dividing this
BigDecimal's unscaled value by the appropriate power of ten to maintain its overall value.
ArithmeticException - if
roundingMode==UNNECESSARY and the specified scaling operation would require rounding.
RoundingMode
public BigDecimalsetScale(int newScale, int roundingMode)
BigDecimal whose scale is the specified value, and whose unscaled value is determined by multiplying or dividing this
BigDecimal's unscaled value by the appropriate power of ten to maintain its overall value. If the scale is reduced by the operation, the unscaled value must be divided (rather than multiplied), and the value may be changed; in this case, the specified rounding mode is applied to the division.
Note that since BigDecimal objects are immutable, calls of this method do not result in the original object being modified, contrary to the usual convention of having methods named setX mutate field X. Instead, setScale returns an object with the proper scale; the returned object may or may not be newly allocated.
The new setScale(int, RoundingMode) method should be used in preference to this legacy method.
newScale - scale of the
BigDecimal value to be returned.
roundingMode - The rounding mode to apply.
BigDecimal whose scale is the specified value, and whose unscaled value is determined by multiplying or dividing this
BigDecimal's unscaled value by the appropriate power of ten to maintain its overall value.
ArithmeticException - if
roundingMode==ROUND_UNNECESSARY and the specified scaling operation would require rounding.
IllegalArgumentException - if
roundingMode does not represent a valid rounding mode.
ROUND_UP,
ROUND_DOWN,
ROUND_CEILING,
ROUND_FLOOR,
ROUND_HALF_UP,
ROUND_HALF_DOWN,
ROUND_HALF_EVEN,
ROUND_UNNECESSARY
public BigDecimalsetScale(int newScale)
BigDecimal whose scale is the specified value, and whose value is numerically equal to this
BigDecimal's. Throws an
ArithmeticException if this is not possible.
This call is typically used to increase the scale, in which case it is guaranteed that there exists a BigDecimal of the specified scale and the correct value. The call can also be used to reduce the scale if the caller knows that the BigDecimal has sufficiently many zeros at the end of its fractional part (i.e., factors of ten in its integer value) to allow for the rescaling without changing its value.
This method returns the same result as the two-argument versions of setScale, but saves the caller the trouble of specifying a rounding mode in cases where it is irrelevant.
Note that since BigDecimal objects are immutable, calls of this method do not result in the original object being modified, contrary to the usual convention of having methods named setX mutate field X. Instead, setScale returns an object with the proper scale; the returned object may or may not be newly allocated.
newScale - scale of the
BigDecimal value to be returned.
BigDecimal whose scale is the specified value, and whose unscaled value is determined by multiplying or dividing this
BigDecimal's unscaled value by the appropriate power of ten to maintain its overall value.
ArithmeticException - if the specified scaling operation would require rounding.
setScale(int, int),
setScale(int, RoundingMode)
public BigDecimalmovePointLeft(int n)
BigDecimal which is equivalent to this one with the decimal point moved
n places to the left. If
n is non-negative, the call merely adds
n to the scale. If
n is negative, the call is equivalent to
movePointRight(-n). The
BigDecimal returned by this call has value
(this × 10-n) and scale
max(this.scale()+n, 0).
n - number of places to move the decimal point to the left.
BigDecimal which is equivalent to this one with the decimal point moved
n places to the left.
ArithmeticException - if scale overflows.
public BigDecimalmovePointRight(int n)
BigDecimal which is equivalent to this one with the decimal point moved
n places to the right. If
n is non-negative, the call merely subtracts
n from the scale. If
n is negative, the call is equivalent to
movePointLeft(-n). The
BigDecimal returned by this call has value
(this × 10n) and scale
max(this.scale()-n, 0).
n - number of places to move the decimal point to the right.
BigDecimal which is equivalent to this one with the decimal point moved
n places to the right.
ArithmeticException - if scale overflows.
public BigDecimalscaleByPowerOfTen(int n)
this * 10
n). The scale of the result is
(this.scale() - n).
n - the exponent power of ten to scale by
this * 10
n)
ArithmeticException - if the scale would be outside the range of a 32-bit integer.
public BigDecimalstripTrailingZeros()
BigDecimal which is numerically equal to this one but with any trailing zeros removed from the representation. For example, stripping the trailing zeros from the
BigDecimal value
600.0, which has [
BigInteger,
scale] components equals to [6000, 1], yields
6E2 with [
BigInteger,
scale] components equals to [6, -2]. If this BigDecimal is numerically equal to zero, then
BigDecimal.ZERO is returned.
BigDecimal with any trailing zeros removed.
public int compareTo(BigDecimalval)
BigDecimal with the specified
BigDecimal. Two
BigDecimal objects that are equal in value but have a different scale (like 2.0 and 2.00) are considered equal by this method. This method is provided in preference to individual methods for each of the six boolean comparison operators (<, ==, >, >=, !=, <=). The suggested idiom for performing these comparisons is:
(x.compareTo(y) <
op>
0), where <
op> is one of the six comparison operators.
compareTo in interface
Comparable<BigDecimal>
val -
BigDecimal to which this
BigDecimal is to be compared.
BigDecimal is numerically less than, equal to, or greater than
val.
public boolean equals(Objectx)
BigDecimal with the specified
Object for equality. Unlike
compareTo, this method considers two
BigDecimal objects equal only if they are equal in value and scale (thus 2.0 is not equal to 2.00 when compared by this method).
equals in class
Object
x -
Object to which this
BigDecimal is to be compared.
true if and only if the specified
Object is a
BigDecimal whose value and scale are equal to this
BigDecimal's.
compareTo(java.math.BigDecimal),
hashCode()
public BigDecimalmin(BigDecimal val)
BigDecimal and
val.
val - value with which the minimum is to be computed.
BigDecimal whose value is the lesser of this
BigDecimal and
val. If they are equal, as defined by the
compareTo method,
this is returned.
compareTo(java.math.BigDecimal)
public BigDecimalmax(BigDecimal val)
BigDecimal and
val.
val - value with which the maximum is to be computed.
BigDecimal whose value is the greater of this
BigDecimal and
val. If they are equal, as defined by the
compareTo method,
this is returned.
compareTo(java.math.BigDecimal)
public int hashCode()
BigDecimal. Note that two
BigDecimal objects that are numerically equal but differ in scale (like 2.0 and 2.00) will generally
not have the same hash code.
hashCode in class
Object
BigDecimal.
equals(Object)
public StringtoString()
BigDecimal, using scientific notation if an exponent is needed.
A standard canonical string form of the BigDecimal is created as though by the following steps: first, the absolute value of the unscaled value of the BigDecimal is converted to a string in base ten using the characters '0' through '9' with no leading zeros (except if its value is zero, in which case a single '0' character is used).
Next, an adjusted exponent is calculated; this is the negated scale, plus the number of characters in the converted unscaled value, less one. That is, -scale+(ulength-1), where ulength is the length of the absolute value of the unscaled value in decimal digits (its precision).
If the scale is greater than or equal to zero and the adjusted exponent is greater than or equal to -6, the number will be converted to a character form without using exponential notation. In this case, if the scale is zero then no decimal point is added and if the scale is positive a decimal point will be inserted with the scale specifying the number of characters to the right of the decimal point. '0' characters are added to the left of the converted unscaled value as necessary. If no character precedes the decimal point after this insertion then a conventional '0' character is prefixed.
Otherwise (that is, if the scale is negative, or the adjusted exponent is less than -6), the number will be converted to a character form using exponential notation. In this case, if the converted BigInteger has more than one digit a decimal point is inserted after the first digit. An exponent in character form is then suffixed to the converted unscaled value (perhaps with inserted decimal point); this comprises the letter 'E' followed immediately by the adjusted exponent converted to a character form. The latter is in base ten, using the characters '0' through '9' with no leading zeros, and is always prefixed by a sign character '-' ('\u002D') if the adjusted exponent is negative, '+' ('\u002B') otherwise).
Finally, the entire string is prefixed by a minus sign character '-' ('\u002D') if the unscaled value is less than zero. No sign character is prefixed if the unscaled value is zero or positive.
Examples:
For each representation [unscaled value, scale] on the left, the resulting string is shown on the right.
[123,0] "123" [-123,0] "-123" [123,-1] "1.23E+3" [123,-3] "1.23E+5" [123,1] "12.3" [123,5] "0.00123" [123,10] "1.23E-8" [-123,12] "-1.23E-10"Notes:
BigDecimal values and the result of this conversion. That is, every distinguishable BigDecimal value (unscaled value and scale) has a unique string representation as a result of using toString. If that string representation is converted back to a BigDecimal using the BigDecimal(String) constructor, then the original value will be recovered. NumberFormat class and its subclasses. toEngineeringString() method may be used for presenting numbers with exponents in engineering notation, and the setScale method may be used for rounding a BigDecimal so it has a known number of digits after the decimal point. Character.forDigit is used. toString in class
Object
BigDecimal.
Character.forDigit(int, int) ,
BigDecimal(java.lang.String)
public StringtoEngineeringString()
BigDecimal, using engineering notation if an exponent is needed.
Returns a string that represents the BigDecimal as described in the toString() method, except that if exponential notation is used, the power of ten is adjusted to be a multiple of three (engineering notation) such that the integer part of nonzero values will be in the range 1 through 999. If exponential notation is used for zero values, a decimal point and one or two fractional zero digits are used so that the scale of the zero value is preserved. Note that unlike the output of toString(), the output of this method is not guaranteed to recover the same [integer, scale] pair of this BigDecimal if the output string is converting back to a BigDecimal using the string constructor. The result of this method meets the weaker constraint of always producing a numerically equal result from applying the string constructor to the method's output.
BigDecimal, using engineering notation if an exponent is needed.
public StringtoPlainString()
BigDecimal without an exponent field. For values with a positive scale, the number of digits to the right of the decimal point is used to indicate scale. For values with a zero or negative scale, the resulting string is generated as if the value were converted to a numerically equal value with zero scale and as if all the trailing zeros of the zero scale value were present in the result. The entire string is prefixed by a minus sign character '-' (
'\u002D') if the unscaled value is less than zero. No sign character is prefixed if the unscaled value is zero or positive. Note that if the result of this method is passed to the
string constructor, only the numerical value of this
BigDecimal will necessarily be recovered; the representation of the new
BigDecimal may have a different scale. In particular, if this
BigDecimal has a negative scale, the string resulting from this method will have a scale of zero when processed by the string constructor. (This method behaves analogously to the
toString method in 1.4 and earlier releases.)
BigDecimal without an exponent field.
toString(),
toEngineeringString()
public BigIntegertoBigInteger()
BigDecimal to a
BigInteger. This conversion is analogous to the
narrowing primitive conversion from
double to
long as defined in section 5.1.3 of
The Java™ Language Specification: any fractional part of this
BigDecimal will be discarded. Note that this conversion can lose information about the precision of the
BigDecimal value.
To have an exception thrown if the conversion is inexact (in other words if a nonzero fractional part is discarded), use the toBigIntegerExact() method.
BigDecimal converted to a
BigInteger.
public BigIntegertoBigIntegerExact()
BigDecimal to a
BigInteger, checking for lost information. An exception is thrown if this
BigDecimal has a nonzero fractional part.
BigDecimal converted to a
BigInteger.
ArithmeticException - if
this has a nonzero fractional part.
public long longValue()
BigDecimal to a
long. This conversion is analogous to the
narrowing primitive conversion from
double to
short as defined in section 5.1.3 of
The Java™ Language Specification: any fractional part of this
BigDecimal will be discarded, and if the resulting "
BigInteger" is too big to fit in a
long, only the low-order 64 bits are returned. Note that this conversion can lose information about the overall magnitude and precision of this
BigDecimal value as well as return a result with the opposite sign.
public long longValueExact()
BigDecimal to a
long, checking for lost information. If this
BigDecimal has a nonzero fractional part or is out of the possible range for a
long result then an
ArithmeticException is thrown.
BigDecimal converted to a
long.
ArithmeticException - if
this has a nonzero fractional part, or will not fit in a
long.
public int intValue()
BigDecimal to an
int. This conversion is analogous to the
narrowing primitive conversion from
double to
short as defined in section 5.1.3 of
The Java™ Language Specification: any fractional part of this
BigDecimal will be discarded, and if the resulting "
BigInteger" is too big to fit in an
int, only the low-order 32 bits are returned. Note that this conversion can lose information about the overall magnitude and precision of this
BigDecimal value as well as return a result with the opposite sign.
public int intValueExact()
BigDecimal to an
int, checking for lost information. If this
BigDecimal has a nonzero fractional part or is out of the possible range for an
int result then an
ArithmeticException is thrown.
BigDecimal converted to an
int.
ArithmeticException - if
this has a nonzero fractional part, or will not fit in an
int.
public short shortValueExact()
BigDecimal to a
short, checking for lost information. If this
BigDecimal has a nonzero fractional part or is out of the possible range for a
short result then an
ArithmeticException is thrown.
BigDecimal converted to a
short.
ArithmeticException - if
this has a nonzero fractional part, or will not fit in a
short.
public byte byteValueExact()
BigDecimal to a
byte, checking for lost information. If this
BigDecimal has a nonzero fractional part or is out of the possible range for a
byte result then an
ArithmeticException is thrown.
BigDecimal converted to a
byte.
ArithmeticException - if
this has a nonzero fractional part, or will not fit in a
byte.
public float floatValue()
BigDecimal to a
float. This conversion is similar to the
narrowing primitive conversion from
double to
float as defined in section 5.1.3 of
The Java™ Language Specification: if this
BigDecimal has too great a magnitude to represent as a
float, it will be converted to
Float.NEGATIVE_INFINITY or
Float.POSITIVE_INFINITY as appropriate. Note that even when the return value is finite, this conversion can lose information about the precision of the
BigDecimal value.
floatValue in class
Number
BigDecimal converted to a
float.
public double doubleValue()
BigDecimal to a
double. This conversion is similar to the
narrowing primitive conversion from
double to
float as defined in section 5.1.3 of
The Java™ Language Specification: if this
BigDecimal has too great a magnitude represent as a
double, it will be converted to
Double.NEGATIVE_INFINITY or
Double.POSITIVE_INFINITY as appropriate. Note that even when the return value is finite, this conversion can lose information about the precision of the
BigDecimal value.
doubleValue in class
Number
BigDecimal converted to a
double.
public BigDecimalulp()
BigDecimal. An ulp of a nonzero
BigDecimal value is the positive distance between this value and the
BigDecimal value next larger in magnitude with the same number of digits. An ulp of a zero value is numerically equal to 1 with the scale of
this. The result is stored with the same scale as
this so the result for zero and nonzero values is equal to
[1, this.scale()].
this