Generate a random number in C#

This post will discuss how to generate a random number between the specified range in C#.

1. Using `Random` Class

We can use the Random.Next() method that generates a pseudorandomly random value between the specified range. The following code uses the Random.Next() method to generate a random integer between min and max.

using System;

public class Example

{

public static void Main()

{

int min = 1;

int max = 10;

Random rnd = new Random();

Console.WriteLine(rnd.Next(min, max + 1));

}

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2. Using `RNGCryptoServiceProvider` Class

The Random class is not cryptographically secure. To generate a cryptographically secure random value, use the RNGCryptoServiceProvider class or derive a class from System.Security.Cryptography.RandomNumberGenerator.

The RNGCryptoServiceProvider class uses System entropy for generating seeds. Its usage is demonstrated below:

using System;

using System.Security.Cryptography;

public class Example

{

public static int GetRandomNumber()

{

using (RNGCryptoServiceProvider rngCrypt = new RNGCryptoServiceProvider())

{

byte[] tokenBuffer = new byte[4]; // `int32` takes 4 bytes in C#

rngCrypt.GetBytes(tokenBuffer);

return BitConverter.ToInt32(tokenBuffer, 0);

}

public static void Main()

{

int random = GetRandomNumber();

Console.WriteLine(random);

}

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That’s all about generating a random number in C#.

Generate a random number in C#

1. Using Random Class

2. Using RNGCryptoServiceProvider Class

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1. Using `Random` Class

2. Using `RNGCryptoServiceProvider` Class