Generating Random Number and String in C#

Often we have looking for generating random number or random string for some requirement such as captcha validation, sending password in email etc. Here I’m creating a simple example on how to generate random number and random string. Let’s have a look.

using System;

using System.Text;

namespace RandomNumberString

{

    /// <summary>

    /// Generate Random Number and String

    /// </summary>

    class NumbeString

     {

       Random random = new Random();

       StringBuilder builder = new StringBuilder();

       /// <summary>

       /// Method for generate random number

       /// </summary>

       public void RandomNumber()

        {

             Console.WriteLine("Random Number \n" + random.Next(10000));

        }

        /// <summary>

        /// method for generate random string with lower and upper case

        /// </summary>

        /// <param name="size"></param>

        /// <param name="lowerCase"></param>

       public void RandomString()

       {

           char ch;

           for (int i = 0; i < 4; i++)

           {

               ch = Convert.ToChar(Convert.ToInt32(Math.Floor(26 * random.NextDouble() + 65)));// Upper case char

               builder.Append(ch);

               ch = Convert.ToChar(Convert.ToInt32(Math.Floor(26 * random.NextDouble() + 97)));// Lower case char

               builder.Append(ch);

           }

           Console.WriteLine("Random String \n" + builder.ToString());

       } 

    }

    /// <summary>

    /// class for define main method

    /// </summary>

    class String

    {

       static void Main(string[] args)

        {

            NumbeString ns = new NumbeString();

            ns.RandomNumber();

            ns.RandomString();

            Console.ReadLine();

        }

    }

}

Output

 

Build application and execute program. Every Execution new Random number and string will be display. For example

Random Number

2918

Random String

NvPfTaKu

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