BitConverter.DoubleToInt64Bits Method (Double)


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Converts the specified double-precision floating point number to a 64-bit signed integer.

Namespace:   System
Assembly:  mscorlib (in mscorlib.dll)

public static long DoubleToInt64Bits(
	double value


Type: System.Double

The number to convert.

Return Value

Type: System.Int64

A 64-bit signed integer whose value is equivalent to value.

The order of bits in the integer returned by the DoubleToInt64Bits method depends on whether the computer architecture is little-endian or big-endian.

The following code example converts the bit patterns of several Double values to Int64 values with the DoubleToInt64Bits method.

// Example of the BitConverter.DoubleToInt64Bits method.
using System;

class DoubleToInt64BitsDemo
    const string formatter = "{0,25:E16}{1,23:X16}";

    // Reinterpret the double argument as a long.
    public static void DoubleToLongBits( double argument )
        long longValue;
        longValue = BitConverter.DoubleToInt64Bits( argument );

        // Display the resulting long in hexadecimal.
        Console.WriteLine( formatter, argument, longValue );

    public static void Main( )
            "This example of the BitConverter.DoubleToInt64Bits( " +
            "double ) \nmethod generates the following output.\n" );
        Console.WriteLine( formatter, "double argument", 
            "hexadecimal value" );
        Console.WriteLine( formatter, "---------------", 
            "-----------------" );

        // Convert double values and display the results.
        DoubleToLongBits( 1.0 );
        DoubleToLongBits( 15.0 );
        DoubleToLongBits( 255.0 );
        DoubleToLongBits( 4294967295.0 );
        DoubleToLongBits( 0.00390625 );
        DoubleToLongBits( 0.00000000023283064365386962890625 );
        DoubleToLongBits( 1.234567890123E-300 );
        DoubleToLongBits( 1.23456789012345E-150 );
        DoubleToLongBits( 1.2345678901234565 );
        DoubleToLongBits( 1.2345678901234567 );
        DoubleToLongBits( 1.2345678901234569 );
        DoubleToLongBits( 1.23456789012345678E+150 );
        DoubleToLongBits( 1.234567890123456789E+300 );
        DoubleToLongBits( double.MinValue );
        DoubleToLongBits( double.MaxValue );
        DoubleToLongBits( double.Epsilon );
        DoubleToLongBits( double.NaN );
        DoubleToLongBits( double.NegativeInfinity );
        DoubleToLongBits( double.PositiveInfinity );

This example of the BitConverter.DoubleToInt64Bits( double )
method generates the following output.

          double argument      hexadecimal value
          ---------------      -----------------
  1.0000000000000000E+000       3FF0000000000000
  1.5000000000000000E+001       402E000000000000
  2.5500000000000000E+002       406FE00000000000
  4.2949672950000000E+009       41EFFFFFFFE00000
  3.9062500000000000E-003       3F70000000000000
  2.3283064365386963E-010       3DF0000000000000
  1.2345678901230000E-300       01AA74FE1C1E7E45
  1.2345678901234500E-150       20D02A36586DB4BB
  1.2345678901234565E+000       3FF3C0CA428C59FA
  1.2345678901234567E+000       3FF3C0CA428C59FB
  1.2345678901234569E+000       3FF3C0CA428C59FC
  1.2345678901234569E+150       5F182344CD3CDF9F
  1.2345678901234569E+300       7E3D7EE8BCBBD352
 -1.7976931348623157E+308       FFEFFFFFFFFFFFFF
  1.7976931348623157E+308       7FEFFFFFFFFFFFFF
  4.9406564584124654E-324       0000000000000001
                      NaN       FFF8000000000000
                -Infinity       FFF0000000000000
                 Infinity       7FF0000000000000

Universal Windows Platform
Available since 8
.NET Framework
Available since 1.1
Portable Class Library
Supported in: portable .NET platforms
Available since 4.0
Windows Phone Silverlight
Available since 7.1
Windows Phone
Available since 8.1
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