---
title: "Generating Random Number and String in C#"  
description: "Often we have looking for generating random number or random string for some requirement such as captcha validation, sending password in email etc. He"  
author: "AVADHESH PATEL"  
published: 2012-08-09  
updated: 2014-09-18  
canonical: https://www.mindstick.com/blog/331/generating-random-number-and-string-in-c-sharp  
category: "c#"  
tags: ["c#"]  
reading_time: 2 minutes  

---

# Generating Random Number and String in C#

Often we have looking for [generating random](https://www.mindstick.com/forum/23187/generating-random-integers-in-a-range-with-java) number or random [string](https://www.mindstick.com/articles/1527/string-split-in-c-sharp) for some [requirement](https://yourviews.mindstick.com/view/85169/becoming-an-influencer-requirement-of-skills-and-knowledge) such as [captcha](https://www.mindstick.com/news/655/users-to-spend-500-year-s-per-day-on-captcha) [validation](https://www.mindstick.com/articles/12234/validation-using-data-annotation-using-entity-framework), sending [password](https://www.mindstick.com/blog/118/retriving-user-password-by-using-stored-procedure-in-asp-dot-net) in email etc. Here I’m creating a simple example on how to [generate random](https://www.mindstick.com/forum/159580/how-to-generate-random-numbers-in-c-sharp) 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](https://www.mindstick.com/articles/12824/calculator-application-in-android) and [execute](https://www.mindstick.com/interview/49/how-can-i-execute-a-php-script-using-command-line) program. Every [Execution](https://www.mindstick.com/blog/178/synchronous-and-asynchronous-command-execution-in-c-sharp-dot-net) new Random number and string will be display. For example

Random Number

2918

Random String

NvPfTaKu

---

Original Source: https://www.mindstick.com/blog/331/generating-random-number-and-string-in-c-sharp

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