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BitConverter.Int64BitsToDouble Method

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

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

public static double Int64BitsToDouble(
	long value


Type: System.Int64
The number to convert.

Return Value

Type: System.Double
A double-precision floating point number whose value is equivalent to value.

The following code example converts the bit patterns of several Int64 values to Double values with the Int64BitsToDouble method.

// Example of the BitConverter.Int64BitsToDouble method.
using System;

class Int64BitsToDoubleDemo
    const string formatter = "{0,20}{1,27:E16}";

    // Reinterpret the long argument as a double.
    public static void LongBitsToDouble( long argument )
        double doubleValue;
        doubleValue = BitConverter.Int64BitsToDouble( argument );

        // Display the argument in hexadecimal.
        Console.WriteLine( formatter, 
            String.Format( "0x{0:X16}", argument ), doubleValue );

    public static void Main( )
            "This example of the BitConverter.Int64BitsToDouble( " +
            "long ) \nmethod generates the following output.\n" );
        Console.WriteLine( formatter, "long argument", 
            "double value" );
        Console.WriteLine( formatter, "-------------", 
            "------------" );

        // Convert long values and display the results.
        LongBitsToDouble( 0 );
        LongBitsToDouble( 0x3FF0000000000000 );
        LongBitsToDouble( 0x402E000000000000 );
        LongBitsToDouble( 0x406FE00000000000 );
        LongBitsToDouble( 0x41EFFFFFFFE00000 );
        LongBitsToDouble( 0x3F70000000000000 );
        LongBitsToDouble( 0x3DF0000000000000 );
        LongBitsToDouble( 0x0000000000000001 );
        LongBitsToDouble( 0x000000000000FFFF );
        LongBitsToDouble( 0x0000FFFFFFFFFFFF );
        LongBitsToDouble( unchecked( (long)0xFFFFFFFFFFFFFFFF ) );
        LongBitsToDouble( unchecked( (long)0xFFF0000000000000 ) );
        LongBitsToDouble( 0x7FF0000000000000 );
        LongBitsToDouble( unchecked( (long)0xFFEFFFFFFFFFFFFF ) );
        LongBitsToDouble( 0x7FEFFFFFFFFFFFFF );
        LongBitsToDouble( long.MinValue );
        LongBitsToDouble( long.MaxValue );

This example of the BitConverter.Int64BitsToDouble( long )
method generates the following output.

       long argument               double value
       -------------               ------------
  0x0000000000000000    0.0000000000000000E+000
  0x3FF0000000000000    1.0000000000000000E+000
  0x402E000000000000    1.5000000000000000E+001
  0x406FE00000000000    2.5500000000000000E+002
  0x41EFFFFFFFE00000    4.2949672950000000E+009
  0x3F70000000000000    3.9062500000000000E-003
  0x3DF0000000000000    2.3283064365386963E-010
  0x0000000000000001    4.9406564584124654E-324
  0x000000000000FFFF    3.2378592100206092E-319
  0x0000FFFFFFFFFFFF    1.3906711615669959E-309
  0xFFFFFFFFFFFFFFFF                        NaN
  0xFFF0000000000000                  -Infinity
  0x7FF0000000000000                   Infinity
  0xFFEFFFFFFFFFFFFF   -1.7976931348623157E+308
  0x7FEFFFFFFFFFFFFF    1.7976931348623157E+308
  0x8000000000000000    0.0000000000000000E+000
  0x7FFFFFFFFFFFFFFF                        NaN

.NET Framework

Supported in: 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.