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java.math
public class: BigDecimal [javadoc | source]
java.lang.Object
   java.lang.Number
      java.math.BigDecimal

All Implemented Interfaces:
    Comparable, Serializable

Immutable, arbitrary-precision signed decimal numbers. A {@code 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 {@code BigDecimal} is therefore (unscaledValue × 10-scale).

The {@code BigDecimal} class provides operations for arithmetic, scale manipulation, rounding, comparison, hashing, and format conversion. The #toString method provides a canonical representation of a {@code BigDecimal}.

The {@code 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 {@code RoundingMode} {@code enum}, (such as RoundingMode#HALF_UP ) should be used instead.

When a {@code MathContext} object is supplied with a precision setting of 0 (for example, MathContext#UNLIMITED ), arithmetic operations are exact, as are the arithmetic methods which take no {@code 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 {@code 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 {@code 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 {@code 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, {@code BigDecimal} includes many rounding modes, which were mandatory for division in {@code BigDecimal} releases prior to 5. Any conflicts between these ANSI standards and the {@code BigDecimal} specification are resolved in favor of {@code 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 {@code MathContext}'s {@code 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 {@literal "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 {@literal "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.
Preferred Scales for Results of Arithmetic Operations
OperationPreferred Scale of Result
Addmax(addend.scale(), augend.scale())
Subtractmax(minuend.scale(), subtrahend.scale())
Multiplymultiplier.scale() + multiplicand.scale()
Dividedividend.scale() - divisor.scale()
These scales are the ones used by the methods which return exact arithmetic results; except that an exact divide may have to use a larger scale since the exact result may have more digits. For example, {@code 1/32} is {@code 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 {@code 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 {@code precision} digits actually returned. If the exact result can be represented with at most {@code 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 {@code precision} digits by removing trailing zeros and decreasing the scale. For example, rounding to three digits using the {@linkplain RoundingMode#FLOOR floor} rounding mode,
{@code 19/100 = 0.19 // integer=19, scale=2}
but
{@code 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 {@code pow} method using the {@linkplain #pow(int, MathContext) specified algorithm} can occasionally differ from the rounded mathematical result by more than one unit in the last place, one {@linkplain #ulp() ulp}.

Two types of operations are provided for manipulating the scale of a {@code BigDecimal}: scaling/rounding operations and decimal point motion operations. Scaling/rounding operations ( setScale and round ) return a {@code 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 {@code 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 {@code BigDecimal} methods. The pseudo-code expression {@code (i + j)} is shorthand for "a {@code BigDecimal} whose value is that of the {@code BigDecimal} {@code i} added to that of the {@code BigDecimal} {@code j}." The pseudo-code expression {@code (i == j)} is shorthand for "{@code true} if and only if the {@code BigDecimal} {@code i} represents the same value as the {@code BigDecimal} {@code j}." Other pseudo-code expressions are interpreted similarly. Square brackets are used to represent the particular {@code BigInteger} and scale pair defining a {@code BigDecimal} value; for example [19, 2] is the {@code BigDecimal} numerically equal to 0.19 having a scale of 2.

Note: care should be exercised if {@code BigDecimal} objects are used as keys in a SortedMap or elements in a SortedSet since {@code BigDecimal}'s natural ordering is inconsistent with equals. See Comparable , java.util.SortedMap or java.util.SortedSet for more information.

All methods and constructors for this class throw {@code NullPointerException} when passed a {@code null} object reference for any input parameter.

Nested Class Summary:
static class  BigDecimal.StringBuilderHelper   
Field Summary
static final  long INFLATED    Sentinel value for #intCompact indicating the significand information is only available from {@code intVal}. 
public static final  BigDecimal ZERO    The value 0, with a scale of 0.
    since: 1.5 -
 
public static final  BigDecimal ONE    The value 1, with a scale of 0.
    since: 1.5 -
 
public static final  BigDecimal TEN    The value 10, with a scale of 0.
    since: 1.5 -
 
public static final  int ROUND_UP    Rounding mode to round away from zero. Always increments the digit prior to a nonzero discarded fraction. Note that this rounding mode never decreases the magnitude of the calculated value. 
public static final  int ROUND_DOWN    Rounding mode to round towards zero. Never increments the digit prior to a discarded fraction (i.e., truncates). Note that this rounding mode never increases the magnitude of the calculated value. 
public static final  int ROUND_CEILING    Rounding mode to round towards positive infinity. If the {@code BigDecimal} is positive, behaves as for {@code ROUND_UP}; if negative, behaves as for {@code ROUND_DOWN}. Note that this rounding mode never decreases the calculated value. 
public static final  int ROUND_FLOOR    Rounding mode to round towards negative infinity. If the {@code BigDecimal} is positive, behave as for {@code ROUND_DOWN}; if negative, behave as for {@code ROUND_UP}. Note that this rounding mode never increases the calculated value. 
public static final  int ROUND_HALF_UP    Rounding mode to round towards {@literal "nearest neighbor"} unless both neighbors are equidistant, in which case round up. Behaves as for {@code ROUND_UP} if the discarded fraction is ≥ 0.5; otherwise, behaves as for {@code 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    Rounding mode to round towards {@literal "nearest neighbor"} unless both neighbors are equidistant, in which case round down. Behaves as for {@code ROUND_UP} if the discarded fraction is {@literal >} 0.5; otherwise, behaves as for {@code ROUND_DOWN}. 
public static final  int ROUND_HALF_EVEN    Rounding mode to round towards the {@literal "nearest neighbor"} unless both neighbors are equidistant, in which case, round towards the even neighbor. Behaves as for {@code ROUND_HALF_UP} if the digit to the left of the discarded fraction is odd; behaves as for {@code 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    Rounding mode to assert that the requested operation has an exact result, hence no rounding is necessary. If this rounding mode is specified on an operation that yields an inexact result, an {@code ArithmeticException} is thrown. 
Constructor:
 public BigDecimal(char[] in) 
    Parameters:
    in - {@code char} array that is the source of characters.
    Throws:
    NumberFormatException - if {@code in} is not a valid representation of a {@code BigDecimal}.
    since: 1.5 -
 public BigDecimal(String val) 
    Translates the string representation of a {@code BigDecimal} into a {@code BigDecimal}. The string representation consists of an optional sign, {@code '+'} ( '\u002B') or {@code '-'} ('\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 {@code 'e'} ('\u0065') or {@code 'E'} ('\u0045') followed by one or more decimal digits. The value of the exponent must lie between -Integer#MAX_VALUE (Integer#MIN_VALUE +1) and Integer#MAX_VALUE , inclusive.

    More formally, the strings this constructor accepts are described by the following grammar:

    BigDecimalString:
    Signopt Significand Exponentopt

    Sign:
    {@code +}
    {@code -}

    Significand:
    IntegerPart {@code .} FractionPartopt
    {@code .} FractionPart
    IntegerPart

    IntegerPart:
    Digits

    FractionPart:
    Digits

    Exponent:
    ExponentIndicator SignedInteger

    ExponentIndicator:
    {@code e}
    {@code E}

    SignedInteger:
    Signopt Digits

    Digits:
    Digit
    Digits Digit

    Digit:
    any character for which Character#isDigit returns {@code true}, including 0, 1, 2 ...

    The scale of the returned {@code 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 {@code Integer.MIN_VALUE} and {@code Integer.MAX_VALUE}, inclusive.

    The character-to-digit mapping is provided by java.lang.Character#digit set to convert to radix 10. The String may not contain any extraneous characters (whitespace, for example).

    Examples:
    The value of the returned {@code BigDecimal} is equal to significand × 10 exponent. For each string on the left, the resulting representation [{@code BigInteger}, {@code 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 {@code float} and {@code double} NaN and ±Infinity, this constructor is compatible with the values returned by Float#toString and Double#toString . This is generally the preferred way to convert a {@code float} or {@code double} into a BigDecimal, as it doesn't suffer from the unpredictability of the #BigDecimal(double) constructor.

    Parameters:
    val - String representation of {@code BigDecimal}.
    Throws:
    NumberFormatException - if {@code val} is not a valid representation of a {@code BigDecimal}.
 public BigDecimal(double val) 
    Parameters:
    val - {@code double} value to be converted to {@code BigDecimal}.
    Throws:
    NumberFormatException - if {@code val} is infinite or NaN.
 public BigDecimal(BigInteger val) 
    Translates a {@code BigInteger} into a {@code BigDecimal}. The scale of the {@code BigDecimal} is zero.
    Parameters:
    val - {@code BigInteger} value to be converted to {@code BigDecimal}.
 public BigDecimal(int val) 
 public BigDecimal(long val) 
 public BigDecimal(char[] in,
    MathContext mc) 
    Translates a character array representation of a {@code BigDecimal} into a {@code 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 {@code char} array to string and using the {@code BigDecimal(String)} constructor .

    Parameters:
    in - {@code char} array that is the source of characters.
    mc - the context to use.
    Throws:
    ArithmeticException - if the result is inexact but the rounding mode is {@code UNNECESSARY}.
    NumberFormatException - if {@code in} is not a valid representation of a {@code BigDecimal}.
    since: 1.5 -
 public BigDecimal(String val,
    MathContext mc) 
    Translates the string representation of a {@code BigDecimal} into a {@code BigDecimal}, accepting the same strings as the #BigDecimal(String) constructor, with rounding according to the context settings.
    Parameters:
    val - string representation of a {@code BigDecimal}.
    mc - the context to use.
    Throws:
    ArithmeticException - if the result is inexact but the rounding mode is {@code UNNECESSARY}.
    NumberFormatException - if {@code val} is not a valid representation of a BigDecimal.
    since: 1.5 -
 public BigDecimal(double val,
    MathContext mc) 
    Translates a {@code double} into a {@code BigDecimal}, with rounding according to the context settings. The scale of the {@code 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.

    Parameters:
    val - {@code double} value to be converted to {@code BigDecimal}.
    mc - the context to use.
    Throws:
    ArithmeticException - if the result is inexact but the RoundingMode is UNNECESSARY.
    NumberFormatException - if {@code val} is infinite or NaN.
    since: 1.5 -
 public BigDecimal(BigInteger val,
    MathContext mc) 
    Translates a {@code BigInteger} into a {@code BigDecimal} rounding according to the context settings. The scale of the {@code BigDecimal} is zero.
    Parameters:
    val - {@code BigInteger} value to be converted to {@code BigDecimal}.
    mc - the context to use.
    Throws:
    ArithmeticException - if the result is inexact but the rounding mode is {@code UNNECESSARY}.
    since: 1.5 -
 public BigDecimal(BigInteger unscaledVal,
    int scale) 
    Translates a {@code BigInteger} unscaled value and an {@code int} scale into a {@code BigDecimal}. The value of the {@code BigDecimal} is (unscaledVal × 10-scale).
    Parameters:
    unscaledVal - unscaled value of the {@code BigDecimal}.
    scale - scale of the {@code BigDecimal}.
 public BigDecimal(int val,
    MathContext mc) 
    Translates an {@code int} into a {@code BigDecimal}, with rounding according to the context settings. The scale of the {@code BigDecimal}, before any rounding, is zero.
    Parameters:
    val - {@code int} value to be converted to {@code BigDecimal}.
    mc - the context to use.
    Throws:
    ArithmeticException - if the result is inexact but the rounding mode is {@code UNNECESSARY}.
    since: 1.5 -
 public BigDecimal(long val,
    MathContext mc) 
    Translates a {@code long} into a {@code BigDecimal}, with rounding according to the context settings. The scale of the {@code BigDecimal}, before any rounding, is zero.
    Parameters:
    val - {@code long} value to be converted to {@code BigDecimal}.
    mc - the context to use.
    Throws:
    ArithmeticException - if the result is inexact but the rounding mode is {@code UNNECESSARY}.
    since: 1.5 -
 public BigDecimal(char[] in,
    int offset,
    int len) 
    Parameters:
    in - {@code char} array that is the source of characters.
    offset - first character in the array to inspect.
    len - number of characters to consider.
    Throws:
    NumberFormatException - if {@code in} is not a valid representation of a {@code BigDecimal} or the defined subarray is not wholly within {@code in}.
    since: 1.5 -
 public BigDecimal(BigInteger unscaledVal,
    int scale,
    MathContext mc) 
    Translates a {@code BigInteger} unscaled value and an {@code int} scale into a {@code BigDecimal}, with rounding according to the context settings. The value of the {@code BigDecimal} is (unscaledVal × 10-scale), rounded according to the {@code precision} and rounding mode settings.
    Parameters:
    unscaledVal - unscaled value of the {@code BigDecimal}.
    scale - scale of the {@code BigDecimal}.
    mc - the context to use.
    Throws:
    ArithmeticException - if the result is inexact but the rounding mode is {@code UNNECESSARY}.
    since: 1.5 -
 BigDecimal(BigInteger intVal,
    long val,
    int scale,
    int prec) 
    Trusted package private constructor. Trusted simply means if val is INFLATED, intVal could not be null and if intVal is null, val could not be INFLATED.
 public BigDecimal(char[] in,
    int offset,
    int len,
    MathContext mc) 
    Translates a character array representation of a {@code BigDecimal} into a {@code 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 {@code char} array to string and using the {@code BigDecimal(String)} constructor .

    Parameters:
    in - {@code 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.
    Throws:
    ArithmeticException - if the result is inexact but the rounding mode is {@code UNNECESSARY}.
    NumberFormatException - if {@code in} is not a valid representation of a {@code BigDecimal} or the defined subarray is not wholly within {@code in}.
    since: 1.5 -
Method from java.math.BigDecimal Summary:
abs,   abs,   add,   add,   byteValueExact,   compareTo,   divide,   divide,   divide,   divide,   divide,   divide,   divideAndRemainder,   divideAndRemainder,   divideToIntegralValue,   divideToIntegralValue,   doubleValue,   equals,   floatValue,   hashCode,   intValue,   intValueExact,   longValue,   longValueExact,   max,   min,   movePointLeft,   movePointRight,   multiply,   multiply,   negate,   negate,   plus,   plus,   pow,   pow,   precision,   remainder,   remainder,   round,   scale,   scaleByPowerOfTen,   setScale,   setScale,   setScale,   shortValueExact,   signum,   stripTrailingZeros,   subtract,   subtract,   toBigInteger,   toBigIntegerExact,   toEngineeringString,   toPlainString,   toString,   ulp,   unscaledValue,   valueOf,   valueOf,   valueOf
Methods from java.lang.Number:
byteValue,   doubleValue,   floatValue,   intValue,   longValue,   shortValue
Methods from java.lang.Object:
clone,   equals,   finalize,   getClass,   hashCode,   notify,   notifyAll,   toString,   wait,   wait,   wait
Method from java.math.BigDecimal Detail:
 public BigDecimal abs() 
    Returns a {@code BigDecimal} whose value is the absolute value of this {@code BigDecimal}, and whose scale is {@code this.scale()}.
 public BigDecimal abs(MathContext mc) 
    Returns a {@code BigDecimal} whose value is the absolute value of this {@code BigDecimal}, with rounding according to the context settings.
 public BigDecimal add(BigDecimal augend) 
    Returns a {@code BigDecimal} whose value is {@code (this + augend)}, and whose scale is {@code max(this.scale(), augend.scale())}.
 public BigDecimal add(BigDecimal augend,
    MathContext mc) 
    Returns a {@code BigDecimal} whose value is {@code (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.
 public byte byteValueExact() 
    Converts this {@code BigDecimal} to a {@code byte}, checking for lost information. If this {@code BigDecimal} has a nonzero fractional part or is out of the possible range for a {@code byte} result then an {@code ArithmeticException} is thrown.
 public int compareTo(BigDecimal val) 
    Compares this {@code BigDecimal} with the specified {@code BigDecimal}. Two {@code 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 ({@literal <}, ==, {@literal >}, {@literal >=}, !=, {@literal <=}). The suggested idiom for performing these comparisons is: {@code (x.compareTo(y)} <op> {@code 0)}, where <op> is one of the six comparison operators.
 public BigDecimal divide(BigDecimal divisor) 
    Returns a {@code BigDecimal} whose value is {@code (this / divisor)}, and whose preferred scale is {@code (this.scale() - divisor.scale())}; if the exact quotient cannot be represented (because it has a non-terminating decimal expansion) an {@code ArithmeticException} is thrown.
 public BigDecimal divide(BigDecimal divisor,
    int roundingMode) 
    Returns a {@code BigDecimal} whose value is {@code (this / divisor)}, and whose scale is {@code 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.

 public BigDecimal divide(BigDecimal divisor,
    RoundingMode roundingMode) 
    Returns a {@code BigDecimal} whose value is {@code (this / divisor)}, and whose scale is {@code this.scale()}. If rounding must be performed to generate a result with the given scale, the specified rounding mode is applied.
 public BigDecimal divide(BigDecimal divisor,
    MathContext mc) 
    Returns a {@code BigDecimal} whose value is {@code (this / divisor)}, with rounding according to the context settings.
 public BigDecimal divide(BigDecimal divisor,
    int scale,
    int roundingMode) 
    Returns a {@code BigDecimal} whose value is {@code (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.

 public BigDecimal divide(BigDecimal divisor,
    int scale,
    RoundingMode roundingMode) 
    Returns a {@code BigDecimal} whose value is {@code (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.
 public BigDecimal[] divideAndRemainder(BigDecimal divisor) 
    Returns a two-element {@code BigDecimal} array containing the result of {@code divideToIntegralValue} followed by the result of {@code remainder} on the two operands.

    Note that if both the integer quotient and remainder are needed, this method is faster than using the {@code divideToIntegralValue} and {@code remainder} methods separately because the division need only be carried out once.

 public BigDecimal[] divideAndRemainder(BigDecimal divisor,
    MathContext mc) 
    Returns a two-element {@code BigDecimal} array containing the result of {@code divideToIntegralValue} followed by the result of {@code 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 {@code divideToIntegralValue} and {@code remainder} methods separately because the division need only be carried out once.

 public BigDecimal divideToIntegralValue(BigDecimal divisor) 
    Returns a {@code BigDecimal} whose value is the integer part of the quotient {@code (this / divisor)} rounded down. The preferred scale of the result is {@code (this.scale() - divisor.scale())}.
 public BigDecimal divideToIntegralValue(BigDecimal divisor,
    MathContext mc) 
    Returns a {@code BigDecimal} whose value is the integer part of {@code (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 {@code (this.scale() - divisor.scale())}. An {@code ArithmeticException} is thrown if the integer part of the exact quotient needs more than {@code mc.precision} digits.
 public double doubleValue() 
    Converts this {@code BigDecimal} to a {@code double}. This conversion is similar to the narrowing primitive conversion from {@code double} to {@code float} as defined in section 5.1.3 of The Java™ Language Specification: if this {@code BigDecimal} has too great a magnitude represent as a {@code 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 {@code BigDecimal} value.
 public boolean equals(Object x) 
    Compares this {@code BigDecimal} with the specified {@code Object} for equality. Unlike compareTo , this method considers two {@code 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).
 public float floatValue() 
    Converts this {@code BigDecimal} to a {@code float}. This conversion is similar to the narrowing primitive conversion from {@code double} to {@code float} as defined in section 5.1.3 of The Java™ Language Specification: if this {@code BigDecimal} has too great a magnitude to represent as a {@code 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 {@code BigDecimal} value.
 public int hashCode() 
    Returns the hash code for this {@code BigDecimal}. Note that two {@code BigDecimal} objects that are numerically equal but differ in scale (like 2.0 and 2.00) will generally not have the same hash code.
 public int intValue() 
    Converts this {@code BigDecimal} to an {@code int}. This conversion is analogous to the narrowing primitive conversion from {@code double} to {@code short} as defined in section 5.1.3 of The Java™ Language Specification: any fractional part of this {@code BigDecimal} will be discarded, and if the resulting "{@code BigInteger}" is too big to fit in an {@code int}, only the low-order 32 bits are returned. Note that this conversion can lose information about the overall magnitude and precision of this {@code BigDecimal} value as well as return a result with the opposite sign.
 public int intValueExact() 
    Converts this {@code BigDecimal} to an {@code int}, checking for lost information. If this {@code BigDecimal} has a nonzero fractional part or is out of the possible range for an {@code int} result then an {@code ArithmeticException} is thrown.
 public long longValue() 
    Converts this {@code BigDecimal} to a {@code long}. This conversion is analogous to the narrowing primitive conversion from {@code double} to {@code short} as defined in section 5.1.3 of The Java™ Language Specification: any fractional part of this {@code BigDecimal} will be discarded, and if the resulting "{@code BigInteger}" is too big to fit in a {@code long}, only the low-order 64 bits are returned. Note that this conversion can lose information about the overall magnitude and precision of this {@code BigDecimal} value as well as return a result with the opposite sign.
 public long longValueExact() 
    Converts this {@code BigDecimal} to a {@code long}, checking for lost information. If this {@code BigDecimal} has a nonzero fractional part or is out of the possible range for a {@code long} result then an {@code ArithmeticException} is thrown.
 public BigDecimal max(BigDecimal val) 
    Returns the maximum of this {@code BigDecimal} and {@code val}.
 public BigDecimal min(BigDecimal val) 
    Returns the minimum of this {@code BigDecimal} and {@code val}.
 public BigDecimal movePointLeft(int n) 
    Returns a {@code BigDecimal} which is equivalent to this one with the decimal point moved {@code n} places to the left. If {@code n} is non-negative, the call merely adds {@code n} to the scale. If {@code n} is negative, the call is equivalent to {@code movePointRight(-n)}. The {@code BigDecimal} returned by this call has value (this × 10-n) and scale {@code max(this.scale()+n, 0)}.
 public BigDecimal movePointRight(int n) 
    Returns a {@code BigDecimal} which is equivalent to this one with the decimal point moved {@code n} places to the right. If {@code n} is non-negative, the call merely subtracts {@code n} from the scale. If {@code n} is negative, the call is equivalent to {@code movePointLeft(-n)}. The {@code BigDecimal} returned by this call has value (this × 10n) and scale {@code max(this.scale()-n, 0)}.
 public BigDecimal multiply(BigDecimal multiplicand) 
    Returns a {@code BigDecimal} whose value is (this × multiplicand), and whose scale is {@code (this.scale() + multiplicand.scale())}.
 public BigDecimal multiply(BigDecimal multiplicand,
    MathContext mc) 
    Returns a {@code BigDecimal} whose value is (this × multiplicand), with rounding according to the context settings.
 public BigDecimal negate() 
    Returns a {@code BigDecimal} whose value is {@code (-this)}, and whose scale is {@code this.scale()}.
 public BigDecimal negate(MathContext mc) 
    Returns a {@code BigDecimal} whose value is {@code (-this)}, with rounding according to the context settings.
 public BigDecimal plus() 
    Returns a {@code BigDecimal} whose value is {@code (+this)}, and whose scale is {@code this.scale()}.

    This method, which simply returns this {@code BigDecimal} is included for symmetry with the unary minus method #negate() .

 public BigDecimal plus(MathContext mc) 
    Returns a {@code BigDecimal} whose value is {@code (+this)}, with rounding according to the context settings.

    The effect of this method is identical to that of the #round(MathContext) method.

 public BigDecimal pow(int n) 
    Returns a {@code BigDecimal} whose value is (thisn), The power is computed exactly, to unlimited precision.

    The parameter {@code n} must be in the range 0 through 999999999, inclusive. {@code ZERO.pow(0)} returns #ONE . Note that future releases may expand the allowable exponent range of this method.

 public BigDecimal pow(int n,
    MathContext mc) 
    Returns a {@code 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:

    • An {@code ArithmeticException} exception is thrown if
      • {@code abs(n) > 999999999}
      • {@code mc.precision == 0} and {@code n < 0}
      • {@code mc.precision > 0} and {@code n} has more than {@code mc.precision} decimal digits
    • if {@code n} is zero, #ONE is returned even if {@code this} is zero, otherwise
      • if {@code 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 {@code mc} except for a precision increased to {@code mc.precision + elength + 1} where {@code elength} is the number of decimal digits in {@code n}.
      • if {@code n} is negative, the result is calculated as if {@code n} were positive; this value is then divided into one using the working precision specified above.
      • The final value from either the positive or negative case is then rounded to the destination precision.
 public int precision() 
    Returns the precision of this {@code BigDecimal}. (The precision is the number of digits in the unscaled value.)

    The precision of a zero value is 1.

 public BigDecimal remainder(BigDecimal divisor) 
    Returns a {@code BigDecimal} whose value is {@code (this % divisor)}.

    The remainder is given by {@code this.subtract(this.divideToIntegralValue(divisor).multiply(divisor))}. Note that this is not the modulo operation (the result can be negative).

 public BigDecimal remainder(BigDecimal divisor,
    MathContext mc) 
    Returns a {@code BigDecimal} whose value is {@code (this % divisor)}, with rounding according to the context settings. The {@code 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 {@code mc.getPrecision()} digits.

    The remainder is given by {@code this.subtract(this.divideToIntegralValue(divisor, mc).multiply(divisor))}. Note that this is not the modulo operation (the result can be negative).

 public BigDecimal round(MathContext mc) 
    Returns a {@code BigDecimal} rounded according to the {@code 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.

 public int scale() 
    Returns the scale of this {@code 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 {@code -3} means the unscaled value is multiplied by 1000.
 public BigDecimal scaleByPowerOfTen(int n) 
    Returns a BigDecimal whose numerical value is equal to ({@code this} * 10n). The scale of the result is {@code (this.scale() - n)}.
 public BigDecimal setScale(int newScale) 
    Returns a {@code BigDecimal} whose scale is the specified value, and whose value is numerically equal to this {@code BigDecimal}'s. Throws an {@code 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 {@code 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 {@code 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 {@code setScale}, but saves the caller the trouble of specifying a rounding mode in cases where it is irrelevant.

    Note that since {@code 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 {@code X}. Instead, {@code setScale} returns an object with the proper scale; the returned object may or may not be newly allocated.

 public BigDecimal setScale(int newScale,
    RoundingMode roundingMode) 
    Returns a {@code BigDecimal} whose scale is the specified value, and whose unscaled value is determined by multiplying or dividing this {@code 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 {@code X}. Instead, {@code setScale} returns an object with the proper scale; the returned object may or may not be newly allocated.

 public BigDecimal setScale(int newScale,
    int roundingMode) 
    Returns a {@code BigDecimal} whose scale is the specified value, and whose unscaled value is determined by multiplying or dividing this {@code 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 {@code X}. Instead, {@code 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.

 public short shortValueExact() 
    Converts this {@code BigDecimal} to a {@code short}, checking for lost information. If this {@code BigDecimal} has a nonzero fractional part or is out of the possible range for a {@code short} result then an {@code ArithmeticException} is thrown.
 public int signum() 
    Returns the signum function of this {@code BigDecimal}.
 public BigDecimal stripTrailingZeros() 
    Returns a {@code 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 {@code BigDecimal} value {@code 600.0}, which has [{@code BigInteger}, {@code scale}] components equals to [6000, 1], yields {@code 6E2} with [{@code BigInteger}, {@code scale}] components equals to [6, -2]
 public BigDecimal subtract(BigDecimal subtrahend) 
    Returns a {@code BigDecimal} whose value is {@code (this - subtrahend)}, and whose scale is {@code max(this.scale(), subtrahend.scale())}.
 public BigDecimal subtract(BigDecimal subtrahend,
    MathContext mc) 
    Returns a {@code BigDecimal} whose value is {@code (this - subtrahend)}, with rounding according to the context settings. If {@code subtrahend} is zero then this, rounded if necessary, is used as the result. If this is zero then the result is {@code subtrahend.negate(mc)}.
 public BigInteger toBigInteger() 
    Converts this {@code BigDecimal} to a {@code BigInteger}. This conversion is analogous to the narrowing primitive conversion from {@code double} to {@code long} as defined in section 5.1.3 of The Java™ Language Specification: any fractional part of this {@code BigDecimal} will be discarded. Note that this conversion can lose information about the precision of the {@code 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.

 public BigInteger toBigIntegerExact() 
    Converts this {@code BigDecimal} to a {@code BigInteger}, checking for lost information. An exception is thrown if this {@code BigDecimal} has a nonzero fractional part.
 public String toEngineeringString() 
    Returns a string representation of this {@code BigDecimal}, using engineering notation if an exponent is needed.

    Returns a string that represents the {@code 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 {@code BigDecimal} if the output string is converting back to a {@code BigDecimal} using the {@linkplain #BigDecimal(String) 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.

 public String toPlainString() 
    Returns a string representation of this {@code 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 {@linkplain #BigDecimal(String) string constructor}, only the numerical value of this {@code BigDecimal} will necessarily be recovered; the representation of the new {@code BigDecimal} may have a different scale. In particular, if this {@code 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 {@code toString} method in 1.4 and earlier releases.)
 public String toString() 
    Returns the string representation of this {@code BigDecimal}, using scientific notation if an exponent is needed.

    A standard canonical string form of the {@code BigDecimal} is created as though by the following steps: first, the absolute value of the unscaled value of the {@code BigDecimal} is converted to a string in base ten using the characters {@code '0'} through {@code '9'} with no leading zeros (except if its value is zero, in which case a single {@code '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, {@code -scale+(ulength-1)}, where {@code 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 {@code -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. {@code '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 {@code '0'} character is prefixed.

    Otherwise (that is, if the scale is negative, or the adjusted exponent is less than {@code -6}), the number will be converted to a character form using exponential notation. In this case, if the converted {@code 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 {@code 'E'} followed immediately by the adjusted exponent converted to a character form. The latter is in base ten, using the characters {@code '0'} through {@code '9'} with no leading zeros, and is always prefixed by a sign character {@code '-'} ('\u002D') if the adjusted exponent is negative, {@code '+'} ('\u002B') otherwise).

    Finally, the entire string is prefixed by a minus sign character {@code '-'} ('\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:
    1. There is a one-to-one mapping between the distinguishable {@code BigDecimal} values and the result of this conversion. That is, every distinguishable {@code BigDecimal} value (unscaled value and scale) has a unique string representation as a result of using {@code toString}. If that string representation is converted back to a {@code BigDecimal} using the #BigDecimal(String) constructor, then the original value will be recovered.
    2. The string produced for a given number is always the same; it is not affected by locale. This means that it can be used as a canonical string representation for exchanging decimal data, or as a key for a Hashtable, etc. Locale-sensitive number formatting and parsing is handled by the java.text.NumberFormat class and its subclasses.
    3. The #toEngineeringString method may be used for presenting numbers with exponents in engineering notation, and the setScale method may be used for rounding a {@code BigDecimal} so it has a known number of digits after the decimal point.
    4. The digit-to-character mapping provided by {@code Character.forDigit} is used.
 public BigDecimal ulp() 
    Returns the size of an ulp, a unit in the last place, of this {@code BigDecimal}. An ulp of a nonzero {@code BigDecimal} value is the positive distance between this value and the {@code 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 {@code this}. The result is stored with the same scale as {@code this} so the result for zero and nonzero values is equal to {@code [1, this.scale()]}.
 public BigInteger unscaledValue() 
    Returns a {@code BigInteger} whose value is the unscaled value of this {@code BigDecimal}. (Computes (this * 10this.scale()).)
 public static BigDecimal valueOf(long val) 
    Translates a {@code long} value into a {@code BigDecimal} with a scale of zero. This {@literal "static factory method"} is provided in preference to a ({@code long}) constructor because it allows for reuse of frequently used {@code BigDecimal} values.
 public static BigDecimal valueOf(double val) 
    Translates a {@code double} into a {@code BigDecimal}, using the {@code double}'s canonical string representation provided by the Double#toString(double) method.

    Note: This is generally the preferred way to convert a {@code double} (or {@code float}) into a {@code BigDecimal}, as the value returned is equal to that resulting from constructing a {@code BigDecimal} from the result of using Double#toString(double) .

 public static BigDecimal valueOf(long unscaledVal,
    int scale) 
    Translates a {@code long} unscaled value and an {@code int} scale into a {@code BigDecimal}. This {@literal "static factory method"} is provided in preference to a ({@code long}, {@code int}) constructor because it allows for reuse of frequently used {@code BigDecimal} values..