C# - While Loop
A loop statement allows a program to execute a statement(s) multiple times which provides easier and flexible programming. C# has three loop statements:
- While loop
- Do-While loop
- For loop
The While Loop:
While loop allows a set of statements to be executed repeatedly until a given condition is true. The While loop can be viewed as a repeating if statement.
Syntax
while (condition) { statements; }
Flow Diagram:

In below mentioned example, program uses while loop to sum all integers from 1 to 5.
using System; class MyProgram { static void Main(string[] args) { int i = 1; int sum = 0; while (i < 6){ sum = sum + i; i = i+1; } Console.WriteLine(sum); } }
The output of the above code will be:
15
The Do-While Loop:
The Do-While loop in C# is a variant of while loop which execute statements before checking the conditions. Therefore the Do-While loop executes statements at least once.
Syntax
do { statements; } while (condition);
Flow Diagram:

In the below example, even if the condition is not fulfilled, the do-while loop executes the statements once.
using System; class MyProgram { static void Main(string[] args) { int i = 10; int sum = 0; do{ sum = sum + i; i = i+1; } while (i < 6); Console.WriteLine(sum); } }
The output of the above code will be:
10