# BigInteger.OnesComplement(BigInteger) Operator

## Definition

Returns the bitwise one's complement of a BigInteger value.

``````public:
static System::Numerics::BigInteger operator ~(System::Numerics::BigInteger value);``````
``public static System.Numerics.BigInteger operator ~ (System.Numerics.BigInteger value);``
``static member op_OnesComplement : System.Numerics.BigInteger -> System.Numerics.BigInteger``
``Public Shared Operator Not (value As BigInteger) As BigInteger``

#### Parameters

value
BigInteger

An integer value.

#### Returns

BigInteger

The bitwise one's complement of `value`.

## Remarks

The OnesComplement method defines the operation of the bitwise one's complement operator for BigInteger values. The bitwise one's complement operator reverses each bit in a numeric value. That is, bits in `value` that are 0 are set to 1 in the result, and bits that are 1 are set to 0 in the result. The OnesComplement method enables code such as the following:

``````using System;
using System.Numerics;

public class Example
{
public static void Main()
{
BigInteger value, complement;

value = BigInteger.Multiply(BigInteger.One, 9);
complement = ~value;

Console.WriteLine("{0,5} -- {1,-32}", value, DisplayInBinary(value));
Console.WriteLine("{0,5} -- {1,-32}\n", complement, DisplayInBinary(complement));

value = BigInteger.MinusOne * SByte.MaxValue;
complement = ~value;

Console.WriteLine("{0,5} -- {1,-32}", value, DisplayInBinary(value));
Console.WriteLine("{0,5} -- {1,-32}\n", complement, DisplayInBinary(complement));
}

private static string DisplayInBinary(BigInteger number)
{
byte[] bytes = number.ToByteArray();
string binaryString = string.Empty;
foreach (byte byteValue in bytes)
{
string byteString = Convert.ToString(byteValue, 2).Trim();
binaryString += byteString.Insert(0, new string('0', 8 - byteString.Length));
}
return binaryString;
}
}
// The example displays the following output:
//           9 -- 00001001
//         -10 -- 11110110
//
//        -127 -- 10000001
//         126 -- 01111110
``````
``````Imports System.Numerics

Module Example
Public Sub Main()
Dim value, complement As bigInteger

value = BigInteger.Multiply(BigInteger.One, 9)
complement = Not value

Console.WriteLine("{0,5} -- {1,-32}", value, DisplayInBinary(value))
Console.WriteLine("{0,5} -- {1,-32}", complement, DisplayInBinary(complement))
Console.WriteLine()

value = BigInteger.MinusOne * SByte.MaxValue
complement = BigInteger.op_OnesComplement(value)

Console.WriteLine("{0,5} -- {1,-32}", value, DisplayInBinary(value))
Console.WriteLine("{0,5} -- {1,-32}", complement, DisplayInBinary(complement))
Console.WriteLine()
End Sub

Private Function DisplayInBinary(number As BigInteger) As String
Dim bytes() As Byte = number.ToByteArray()
Dim binaryString As String = String.Empty
For Each byteValue As Byte In bytes
Dim byteString As String = Convert.ToString(byteValue, 2).Trim()
binaryString += byteString.Insert(0, New String("0"c, 8 - byteString.Length))
Next
Return binaryString
End Function
End Module
' The example displays the following output:
'           9 -- 00001001
'         -10 -- 11110110
'
'        -127 -- 10000001
'         126 -- 01111110
``````

Languages that do not support custom operators may be able to call the OnesComplement method directly to perform a bitwise one's complement operation. For example:

``````Imports System.Numerics

Module Example
Public Sub Main()
Dim value, complement As bigInteger

value = BigInteger.Multiply(BigInteger.One, 9)
complement = BigInteger.op_OnesComplement(value)

Console.WriteLine("{0,5} -- {1,-32}", value, DisplayInBinary(value))
Console.WriteLine("{0,5} -- {1,-32}", complement, DisplayInBinary(complement))
Console.WriteLine()

value = BigInteger.MinusOne * SByte.MaxValue
complement = BigInteger.op_OnesComplement(value)

Console.WriteLine("{0,5} -- {1,-32}", value, DisplayInBinary(value))
Console.WriteLine("{0,5} -- {1,-32}", complement, DisplayInBinary(complement))
Console.WriteLine()
End Sub

Private Function DisplayInBinary(number As BigInteger) As String
Dim bytes() As Byte = number.ToByteArray()
Dim binaryString As String = String.Empty
For Each byteValue As Byte In bytes
Dim byteString As String = Convert.ToString(byteValue, 2).Trim()
binaryString += byteString.Insert(0, New String("0"c, 8 - byteString.Length))
Next
Return binaryString
End Function
End Module
' The example displays the following output:
'           9 -- 00001001
'         -10 -- 11110110
'
'        -127 -- 10000001
'         126 -- 01111110
``````