Random.NextBytes Random.NextBytes Random.NextBytes Random.NextBytes Method

Definition

Overloads

NextBytes(Byte[]) NextBytes(Byte[]) NextBytes(Byte[]) NextBytes(Byte[])

Fills the elements of a specified array of bytes with random numbers.

NextBytes(Span<Byte>) NextBytes(Span<Byte>) NextBytes(Span<Byte>) NextBytes(Span<Byte>)

NextBytes(Byte[]) NextBytes(Byte[]) NextBytes(Byte[]) NextBytes(Byte[])

Fills the elements of a specified array of bytes with random numbers.

public:
 virtual void NextBytes(cli::array <System::Byte> ^ buffer);
public virtual void NextBytes (byte[] buffer);
abstract member NextBytes : byte[] -> unit
override this.NextBytes : byte[] -> unit
Public Overridable Sub NextBytes (buffer As Byte())

Parameters

buffer
Byte[]

An array of bytes to contain random numbers.

Exceptions

Examples

The following example demonstrates how to use the NextBytes method to fill an array of bytes with random byte values.

#using <System.DLL>

using namespace System;

void main()
{
   Random^ rnd = gcnew Random;
   array<unsigned char>^b = gcnew array<unsigned char>(10);
   rnd->NextBytes( b );
   Console::WriteLine("The Random bytes are:");
   for ( int i = 0; i < 10; i++ )
      Console::WriteLine("{0}: {1}", i, b[i]);
}
// The example displays output similar to the following:
//       The Random bytes are:
//       0: 131
//       1: 96
//       2: 226
//       3: 213
//       4: 176
//       5: 208
//       6: 99
//       7: 89
//       8: 226
//       9: 194
Random rnd = new Random();
Byte[] b = new Byte[10];
rnd.NextBytes(b);
Console.WriteLine("The Random bytes are: ");
for (int i = 0; i <= b.GetUpperBound(0); i++) 
    Console.WriteLine("{0}: {1}", i, b[i]);  

// The example displays output similar to the following:
//       The Random bytes are:
//       0: 131
//       1: 96
//       2: 226
//       3: 213
//       4: 176
//       5: 208
//       6: 99
//       7: 89
//       8: 226
//       9: 194
Public Class Example
    Public Shared Sub Main()
        Dim rnd As New Random()
        Dim b(9) As Byte
        rnd.NextBytes(b)
        Console.WriteLine("The Random bytes are: ")
        For i As Integer = 0 To b.GetUpperBound(0)
            Console.WriteLine("{0}: {1}", i, b(i))
        Next
    End Sub 
End Class 
' The example displays output similar to the following:
'       The Random bytes are:
'       0: 131
'       1: 96
'       2: 226
'       3: 213
'       4: 176
'       5: 208
'       6: 99
'       7: 89
'       8: 226
'       9: 194

Remarks

Each element of the array of bytes is set to a random number greater than or equal to 0, and less than or equal to MaxValue.

For example, to generate a cryptographically secured random number suitable for creating a random password, use a method such as RNGCryptoServiceProvider.GetBytes.

Notes to Inheritors

Starting with the .NET Framework version 2.0, if you derive a class from Random and override the Sample() method, the distribution provided by the derived class implementation of the Sample() method is not used in calls to the base class implementation of the NextBytes(Byte[]) method. Instead, the uniform distribution returned by the base Random class is used. This behavior improves the overall performance of the Random class. To modify this behavior to call the Sample() method in the derived class, you must also override the NextBytes(Byte[]) method.

See also

NextBytes(Span<Byte>) NextBytes(Span<Byte>) NextBytes(Span<Byte>) NextBytes(Span<Byte>)

public:
 virtual void NextBytes(Span<System::Byte> buffer);
public virtual void NextBytes (Span<byte> buffer);
abstract member NextBytes : Span<byte> -> unit
override this.NextBytes : Span<byte> -> unit
Public Overridable Sub NextBytes (buffer As Span(Of Byte))

Parameters

buffer
Span<Byte>

Applies to