Generating Random Numbers in C#

In C#, we can use many ways to generate random numbers. It is very easy when we use the in-built methods from C#.

1. Generating a Random Integer:

The below code snippet generates a random integer between 0 and Int32.MaxValue.

Random random = new Random(); 
int randomNumber = random.Next(); 

2. Generating a Random Integer within a Specified Range:

This method generates a random integer between 1 (inclusive) and 100 (exclusive)

Random random = new Random(); 
int randomNumberInRange = random.Next(1, 100); 

3. Generating a Random Double:

This method generates a random double between 0.0 and 1.0

Random random = new Random(); 
double randomDouble = random.NextDouble(); 

4. Generating a Random Double within a Specified Range:

You can scale and shift the result of random.NextDouble() to fit a specific range and it generates a random double between min and max

Random random = new Random(); 
double min = 5.0;
double max = 10.0; 
double randomDoubleInRange = random.NextDouble() * (max - min) + min; 

Simple Program with all the above methods:

using System;

class Program
{
    static void Main()
    {
        Random random = new Random();

        // Method 1: Generate a random integer
        int randomInt = random.Next();
        Console.WriteLine("Random Integer: " + randomInt);

        // Method 2: Generate a random integer within a specified range
        int randomIntInRange = random.Next(1, 100);
        Console.WriteLine("Random Integer between 1 and 100: " + randomIntInRange);

        // Method 3: Generate a random double
        double randomDouble = random.NextDouble();
        Console.WriteLine("Random Double: " + randomDouble);

        // Method 4: Generate a random double within a specified range
        double min = 5.0;
        double max = 10.0;
        double randomDoubleInRange = random.NextDouble() * (max - min) + min;
        Console.WriteLine("Random Double between 5.0 and 10.0: " + randomDoubleInRange);
        Console.ReadKey();        
    }
}

Output:

Random Integer: 1275583585
Random Integer between 1 and 100: 43
Random Double: 0.36879271332584
Random Double between 5.0 and 10.0: 9.30931732492024