C# while Loop Statement with Examples

How to use a while Loop Statement in C#

This tutorial describes how to use a while loop statement in C#.

A while loop is a control flow statement to execute a block of code while a specified condition evaluates to true. A while loop can execute zero or more times. 

If you need to break out the loop, use the break statement.

Related tutorials:

The while Loop Syntax

The syntax of the while loop is as follows:

while (condition) 
{
   //Block of code
}

Examples

Example 1

The following example shows you how to write the while loop statement to print out each value in the array:

using System;
 
namespace WhileLoopExample
{
    class Program
    {
        static void Main(string[] args)
        {
            string[] strings = new string[]
            {
                "D", "A", "C", "B", "E", "F"
            };
            int i = 0;
            while (i < strings.Length)
            {
                Console.WriteLine(strings[i]);
                i++;
            }
        }
    }
}

Output:

D
A
C
B
E
F

Example 2

The following example shows you how to find the sum of numbers from 1 to 100 by using the while loop:

using System;
 
namespace WhileLoopExample
{
    class Program
    {
        static void Main(string[] args)
        {
            int total = 0;
            int i = 1;
            while (i <= 100)
            {
                total += i;
                i++;
            }
            Console.WriteLine("Total: " + total);
        }
    }
}

Output:

Total: 5050

Example 3

The following example shows you how to break out the loop by using the break statement:

using System;
 
namespace WhileLoopExample
{
    class Program
    {
        static void Main(string[] args)
        {
            int[] numbers = new int[]
            {
                10, 20, 60, 40, 50, 90, 70, 80, 100, 30
            };
            int i = 0;
            while (true)
            {
                Console.WriteLine(numbers[i]);
                if (i == numbers.Length - 5)
                {
                    break;
                }
                i++;
            }
        }
    }
}

The above sample program print out the first six numbers in the array.

Output:

10
20
60
40
50
90

Example 4

You can also use the continue statement inside a while loop, as the following code shows:

using System;
 
namespace WhileLoopExample
{
    class Program
    {
        static void Main(string[] args)
        {
            string[] students = new string[]
            {
                "Student A", "Student B", "Student C", "Student D", "Student E", "Student F"
            };
            int i = 0;
            while (i < students.Length)
            {
                if (i < students.Length - 2)
                {
                    i++;
                    continue;
                }
                else
                {
                    Console.WriteLine(students[i]);
                    i++;
                }
            }
        }
    }
}
 

Output:

Student E
Student F

More C# tutorials:

  • C# switch-case statements
  • C# if-else statements

In this tutorial, you have learned how to use a while loop statement.

A while loop is a control flow statement to execute a block of code repeatedly while a specified condition evaluates to true. A while loop can execute a block of code zero or more times. If you need to break out the loop, you can use the break statement. You can also use the continue statement inside a while loop.


See also:
What is StringBuilder in C# and How to Use it
C# Read Text File with StreamReader
C# Write to File with the File Class and StreamWriter
C# switch case Statements with Examples
C# if-else Statements with Examples