Double

BYTES

static val BYTES: Int

The number of bytes used to represent a double value.

Value: 8

MAX_EXPONENT

static val MAX_EXPONENT: Int

Maximum exponent a finite double variable may have. It is equal to the value returned by Math.getExponent(Double.MAX_VALUE).

Value: 1023

MAX_VALUE

static val MAX_VALUE: Double

A constant holding the largest positive finite value of type double, (2-2-52)·21023. It is equal to the hexadecimal floating-point literal 0x1.fffffffffffffP+1023 and also equal to Double.longBitsToDouble(0x7fefffffffffffffL).

Value: 1.7976931348623157E308

MIN_EXPONENT

static val MIN_EXPONENT: Int

Minimum exponent a normalized double variable may have. It is equal to the value returned by Math.getExponent(Double.MIN_NORMAL).

Value: -1022

MIN_NORMAL

static val MIN_NORMAL: Double

A constant holding the smallest positive normal value of type double, 2-1022. It is equal to the hexadecimal floating-point literal 0x1.0p-1022 and also equal to Double.longBitsToDouble(0x0010000000000000L).

Value: 2.2250738585072014E-308

MIN_VALUE

static val MIN_VALUE: Double

A constant holding the smallest positive nonzero value of type double, 2-1074. It is equal to the hexadecimal floating-point literal 0x0.0000000000001P-1022 and also equal to Double.longBitsToDouble(0x1L).

Value: 4.9E-324

NEGATIVE_INFINITY

static val NEGATIVE_INFINITY: Double

A constant holding the negative infinity of type double. It is equal to the value returned by Double.longBitsToDouble(0xfff0000000000000L).

Value: (-1.0/0.0)

NaN

static val NaN: Double

A constant holding a Not-a-Number (NaN) value of type double. It is equivalent to the value returned by Double.longBitsToDouble(0x7ff8000000000000L).

Value: (0.0/0.0)

POSITIVE_INFINITY

static val POSITIVE_INFINITY: Double

A constant holding the positive infinity of type double. It is equal to the value returned by Double.longBitsToDouble(0x7ff0000000000000L).

Value: (1.0/0.0)

PRECISION

static val PRECISION: Int

The number of bits in the significand of a double value. This is the parameter N in section {@jls 4.2.3} of The Java Language Specification.

Value: 53

SIZE

static val SIZE: Int

The number of bits used to represent a double value.

Value: 64

Double

Double(value: Double)

Deprecated: It is rarely appropriate to use this constructor. The static factory valueOf(double) is generally a better choice, as it is likely to yield significantly better space and time performance.

Constructs a newly allocated Double object that represents the primitive double argument.

Double

Double(s: String)

Deprecated: It is rarely appropriate to use this constructor. Use parseDouble(java.lang.String) to convert a string to a double primitive, or use valueOf(java.lang.String) to convert a string to a Double object.

Constructs a newly allocated Double object that represents the floating-point value of type double represented by the string. The string is converted to a double value as if by the valueOf method.

compare

static fun compare(
    d1: Double, 
    d2: Double
): Int

Compares the two specified double values. The sign of the integer value returned is the same as that of the integer that would be returned by the call:

new Double(d1).compareTo(new Double(d2))
  

compareTo

fun compareTo(other: Double): Int

Compares two Double objects numerically. This method imposes a total order on Double objects with two differences compared to the incomplete order defined by the Java language numerical comparison operators (<, <=, ==, >=, >) on double values.

• A NaN is unordered with respect to other values and unequal to itself under the comparison operators. This method chooses to define Double.NaN to be equal to itself and greater than all other double values (including Double.POSITIVE_INFINITY).
• Positive zero and negative zero compare equal numerically, but are distinct and distinguishable values. This method chooses to define positive zero (+0.0d), to be greater than negative zero (-0.0d).

doubleToLongBits

static fun doubleToLongBits(value: Double): Long

Returns a representation of the specified floating-point value according to the IEEE 754 floating-point "double format" bit layout.

Bit 63 (the bit that is selected by the mask 0x8000000000000000L) represents the sign of the floating-point number. Bits 62-52 (the bits that are selected by the mask 0x7ff0000000000000L) represent the exponent. Bits 51-0 (the bits that are selected by the mask 0x000fffffffffffffL) represent the significand (sometimes called the mantissa) of the floating-point number.

If the argument is positive infinity, the result is 0x7ff0000000000000L.

If the argument is negative infinity, the result is 0xfff0000000000000L.

If the argument is NaN, the result is 0x7ff8000000000000L.

In all cases, the result is a long integer that, when given to the longBitsToDouble(long) method, will produce a floating-point value the same as the argument to doubleToLongBits (except all NaN values are collapsed to a single "canonical" NaN value).

doubleToRawLongBits

static fun doubleToRawLongBits(value: Double): Long

Returns a representation of the specified floating-point value according to the IEEE 754 floating-point "double format" bit layout, preserving Not-a-Number (NaN) values.

Bit 63 (the bit that is selected by the mask 0x8000000000000000L) represents the sign of the floating-point number. Bits 62-52 (the bits that are selected by the mask 0x7ff0000000000000L) represent the exponent. Bits 51-0 (the bits that are selected by the mask 0x000fffffffffffffL) represent the significand (sometimes called the mantissa) of the floating-point number.

If the argument is positive infinity, the result is 0x7ff0000000000000L.

If the argument is negative infinity, the result is 0xfff0000000000000L.

If the argument is NaN, the result is the long integer representing the actual NaN value. Unlike the doubleToLongBits method, doubleToRawLongBits does not collapse all the bit patterns encoding a NaN to a single "canonical" NaN value.

In all cases, the result is a long integer that, when given to the longBitsToDouble(long) method, will produce a floating-point value the same as the argument to doubleToRawLongBits.

equals

fun equals(other: Any?): Boolean

Compares this object against the specified object. The result is true if and only if the argument is not null and is a Double object that represents a double that has the same value as the double represented by this object. For this purpose, two double values are considered to be the same if and only if the method doubleToLongBits(double) returns the identical long value when applied to each.

hashCode

fun hashCode(): Int

Returns a hash code for this Double object. The result is the exclusive OR of the two halves of the long integer bit representation, exactly as produced by the method doubleToLongBits(double), of the primitive double value represented by this Double object. That is, the hash code is the value of the expression: (int)(v^(v>>>32)) where v is defined by: long v = Double.doubleToLongBits(this.doubleValue());

hashCode

static fun hashCode(value: Double): Int

Returns a hash code for a double value; compatible with Double.hashCode().

isFinite

static fun isFinite(d: Double): Boolean

Returns true if the argument is a finite floating-point value; returns false otherwise (for NaN and infinity arguments).

isInfinite

fun isInfinite(): Boolean

Returns true if this Double value is infinitely large in magnitude, false otherwise.

isInfinite

static fun isInfinite(v: Double): Boolean

Returns true if the specified number is infinitely large in magnitude, false otherwise.

isNaN

fun isNaN(): Boolean

Returns true if this Double value is a Not-a-Number (NaN), false otherwise.

isNaN

static fun isNaN(v: Double): Boolean

Returns true if the specified number is a Not-a-Number (NaN) value, false otherwise.

longBitsToDouble

static fun longBitsToDouble(bits: Long): Double

Returns the double value corresponding to a given bit representation. The argument is considered to be a representation of a floating-point value according to the IEEE 754 floating-point "double format" bit layout.

If the argument is 0x7ff0000000000000L, the result is positive infinity.

If the argument is 0xfff0000000000000L, the result is negative infinity.

If the argument is any value in the range 0x7ff0000000000001L through 0x7fffffffffffffffL or in the range 0xfff0000000000001L through 0xffffffffffffffffL, the result is a NaN. No IEEE 754 floating-point operation provided by Java can distinguish between two NaN values of the same type with different bit patterns. Distinct values of NaN are only distinguishable by use of the Double.doubleToRawLongBits method.

In all other cases, let s, e, and m be three values that can be computed from the argument:

<code>int s = ((bits &gt;&gt; 63) == 0) ? 1 : -1;
  int e = (int)((bits &gt;&gt; 52) &amp; 0x7ffL);
  long m = (e == 0) ?
                  (bits &amp; 0xfffffffffffffL) &lt;&lt; 1 :
                  (bits &amp; 0xfffffffffffffL) | 0x10000000000000L;
  </code>

Note that this method may not be able to return a double NaN with exactly same bit pattern as the long argument. IEEE 754 distinguishes between two kinds of NaNs, quiet NaNs and signaling NaNs. The differences between the two kinds of NaN are generally not visible in Java. Arithmetic operations on signaling NaNs turn them into quiet NaNs with a different, but often similar, bit pattern. However, on some processors merely copying a signaling NaN also performs that conversion. In particular, copying a signaling NaN to return it to the calling method may perform this conversion. So longBitsToDouble may not be able to return a double with a signaling NaN bit pattern. Consequently, for some long values, doubleToRawLongBits(longBitsToDouble(start)) may not equal start. Moreover, which particular bit patterns represent signaling NaNs is platform dependent; although all NaN bit patterns, quiet or signaling, must be in the NaN range identified above.

max

static fun max(
    a: Double, 
    b: Double
): Double

Returns the greater of two double values as if by calling Math.max.

min

static fun min(
    a: Double, 
    b: Double
): Double

Returns the smaller of two double values as if by calling Math.min.

parseDouble

static fun parseDouble(s: String): Double

Returns a new double initialized to the value represented by the specified String, as performed by the valueOf method of class Double.

sum

static fun sum(
    a: Double, 
    b: Double
): Double

Adds two double values together as per the + operator.

toByte

fun toByte(): Byte

Returns the value of this Double as a byte after a narrowing primitive conversion.

toDouble

fun toDouble(): Double

Returns the double value of this Double object.

toFloat

fun toFloat(): Float

Returns the value of this Double as a float after a narrowing primitive conversion.

toHexString

static fun toHexString(d: Double): String

Returns a hexadecimal string representation of the double argument. All characters mentioned below are ASCII characters.

• If the argument is NaN, the result is the string "NaN".
• Otherwise, the result is a string that represents the sign and magnitude of the argument. If the sign is negative, the first character of the result is '-' ('\u005Cu002D'); if the sign is positive, no sign character appears in the result. As for the magnitude m:
  • If m is infinity, it is represented by the string "Infinity"; thus, positive infinity produces the result "Infinity" and negative infinity produces the result "-Infinity".
  • If m is zero, it is represented by the string "0x0.0p0"; thus, negative zero produces the result "-0x0.0p0" and positive zero produces the result "0x0.0p0".
  • If m is a double value with a normalized representation, substrings are used to represent the significand and exponent fields. The significand is represented by the characters "0x1." followed by a lowercase hexadecimal representation of the rest of the significand as a fraction. Trailing zeros in the hexadecimal representation are removed unless all the digits are zero, in which case a single zero is used. Next, the exponent is represented by "p" followed by a decimal string of the unbiased exponent as if produced by a call to Integer.toString on the exponent value.
  • If m is a double value with a subnormal representation, the significand is represented by the characters "0x0." followed by a hexadecimal representation of the rest of the significand as a fraction. Trailing zeros in the hexadecimal representation are removed. Next, the exponent is represented by "p-1022". Note that there must be at least one nonzero digit in a subnormal significand.

toInt

fun toInt(): Int

Returns the value of this Double as an int after a narrowing primitive conversion.

toLong

fun toLong(): Long

Returns the value of this Double as a long after a narrowing primitive conversion.

toShort

fun toShort(): Short

Returns the value of this Double as a short after a narrowing primitive conversion.

toString

fun toString(): String

Returns a string representation of this Double object. The primitive double value represented by this object is converted to a string exactly as if by the method toString of one argument.

toString

static fun toString(d: Double): String

Returns a string representation of the double argument. All characters mentioned below are ASCII characters.

• If the argument is NaN, the result is the string "NaN".
• Otherwise, the result is a string that represents the sign and magnitude (absolute value) of the argument. If the sign is negative, the first character of the result is '-' ('\u005Cu002D'); if the sign is positive, no sign character appears in the result. As for the magnitude m:
  • If m is infinity, it is represented by the characters "Infinity"; thus, positive infinity produces the result "Infinity" and negative infinity produces the result "-Infinity".
  • If m is zero, it is represented by the characters "0.0"; thus, negative zero produces the result "-0.0" and positive zero produces the result "0.0".
  • If m is greater than or equal to 10-3 but less than 107, then it is represented as the integer part of m, in decimal form with no leading zeroes, followed by '.' ('\u005Cu002E'), followed by one or more decimal digits representing the fractional part of m.
  • If m is less than 10-3 or greater than or equal to 107, then it is represented in so-called "computerized scientific notation." Let n be the unique integer such that 10n ≤ m < 10n+1; then let a be the mathematically exact quotient of m and 10n so that 1 ≤ a < 10. The magnitude is then represented as the integer part of a, as a single decimal digit, followed by '.' ('\u005Cu002E'), followed by decimal digits representing the fractional part of a, followed by the letter 'E' ('\u005Cu0045'), followed by a representation of n as a decimal integer, as produced by the method Integer#toString(int).

To create localized string representations of a floating-point value, use subclasses of java.text.NumberFormat.

valueOf

static fun valueOf(s: String): Double

Returns a object holding the value represented by the argument string .

If s is null, then a NullPointerException is thrown.

Leading and trailing whitespace characters in s are ignored. Whitespace is removed as if by the java.lang.String#trim method; that is, both ASCII space and control characters are removed. The rest of s should constitute a FloatValue as described by the lexical syntax rules:

FloatValue:

Signopt NaN

Signopt Infinity

Signopt FloatingPointLiteral

Signopt HexFloatingPointLiteral

SignedInteger

HexFloatingPointLiteral:

HexSignificand BinaryExponent FloatTypeSuffixopt

HexSignificand:

HexNumeral

HexNumeral .

0x HexDigitsopt . HexDigits

0X HexDigitsopt . HexDigits

BinaryExponent:

BinaryExponentIndicator SignedInteger

BinaryExponentIndicator:

p

P

To interpret localized string representations of a floating-point value, use subclasses of .

Note that trailing format specifiers, specifiers that determine the type of a floating-point literal (1.0f is a float value; 1.0d is a double value), do not influence the results of this method. In other words, the numerical value of the input string is converted directly to the target floating-point type. The two-step sequence of conversions, string to float followed by float to double, is not equivalent to converting a string directly to double. For example, the float literal 0.1f is equal to the double value 0.10000000149011612; the float literal 0.1f represents a different numerical value than the double literal 0.1. (The numerical value 0.1 cannot be exactly represented in a binary floating-point number.)

To avoid calling this method on an invalid string and having a NumberFormatException be thrown, the regular expression below can be used to screen the input string:

<code>final String Digits     = "(\\p{Digit}+)";
   final String HexDigits  = "(\\p{XDigit}+)";
   // an exponent is 'e' or 'E' followed by an optionally
   // signed decimal integer.
   final String Exp        = "[eE][+-]?"+Digits;
   final String fpRegex    =
       ("[\\x00-\\x20]*"+  // Optional leading "whitespace"
        "[+-]?(" + // Optional sign character
        "NaN|" +           // "NaN" string
        "Infinity|" +      // "Infinity" string
 
        // A decimal floating-point string representing a finite positive
        // number without a leading sign has at most five basic pieces:
        // Digits . Digits ExponentPart FloatTypeSuffix
        //
        // Since this method allows integer-only strings as input
        // in addition to strings of floating-point literals, the
        // two sub-patterns below are simplifications of the grammar
        // productions from section 3.10.2 of
        // The Java Language Specification.
 
        // Digits ._opt Digits_opt ExponentPart_opt FloatTypeSuffix_opt
        "((("+Digits+"(\\.)?("+Digits+"?)("+Exp+")?)|"+
 
        // . Digits ExponentPart_opt FloatTypeSuffix_opt
        "(\\.("+Digits+")("+Exp+")?)|"+
 
        // Hexadecimal strings
        "((" +
         // 0[xX] HexDigits ._opt BinaryExponent FloatTypeSuffix_opt
         "(0[xX]" + HexDigits + "(\\.)?)|" +
 
         // 0[xX] HexDigits_opt . HexDigits BinaryExponent FloatTypeSuffix_opt
         "(0[xX]" + HexDigits + "?(\\.)" + HexDigits + ")" +
 
         ")[pP][+-]?" + Digits + "))" +
        "[fFdD]?))" +
        "[\\x00-\\x20]*");// Optional trailing "whitespace"
 
   if (Pattern.matches(fpRegex, myString))
       Double.valueOf(myString); // Will not throw NumberFormatException
   else {
       // Perform suitable alternative action
   }
  </code>

valueOf

static fun valueOf(d: Double): Double

Returns a Double instance representing the specified double value. If a new Double instance is not required, this method should generally be used in preference to the constructor Double(double), as this method is likely to yield significantly better space and time performance by caching frequently requested values.

TYPE

static val TYPE: Class<Double!>!

The Class instance representing the primitive type double.