BitConverter.Int64BitsToDouble Method (Int64)


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.

Typically, value is an integer that is returned by the DoubleToInt64Bits method.

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

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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