C# Generate Random Number Function

In this article, I give 3 functions that generate random number based on System.Random() class. All of them are written in CSharp (C#) and demonstration are also in an ASP.NET page.

1. Function returns a non negative random number

    public int GetRandomNumber()
    {
        return new System.Random().Next();
    }

2. Function returns a non negative random number less than a specified maximum number (upperBound)

 
    public int GetRandomNumber(int upperBound)
    {
        return new System.Random().Next(upperBound);
    }

3. Function returns a non negative random number within a specified range (lowerBound and upperBound)

    public int GetRandomNumber(int lowerBound, int upperBound)
    {
        return new System.Random().Next(lowerBound, upperBound + 1);
    }

All together and demonstration in ASP.NET

using System;
using System.Collections.Generic;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
 
public partial class random_number_function : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        int random_number_1 = GetRandomNumber();
 
        Response.Write("random_number_1: " + random_number_1.ToString() + "<br>");
 
        int random_number_2 = GetRandomNumber(1000);
 
        Response.Write("random_number_2: " + random_number_2.ToString() + "<br>");
 
        int random_number_3 = GetRandomNumber(1000,2000);
 
        Response.Write("random_number_3: " + random_number_3.ToString() + "<br>");
 
    }
 
    public int GetRandomNumber(int lowerBound, int upperBound)
    {
        return new System.Random().Next(lowerBound, upperBound + 1);
    }
 
    public int GetRandomNumber(int upperBound)
    {
        return new System.Random().Next(upperBound);
    }
 
    public int GetRandomNumber()
    {
        return new System.Random().Next();
    }
}

Output:

random_number_1: 767015675
random_number_2: 357
random_number_3: -643

Jan 10, 2012Hoan Huynh

Hoan Huynh

Hoan Huynh is the founder and head of 4rapiddev.com. Reach him at [email protected]

9 years ago CSharpRandom202