while loop :

One of the simplest and most commonly used loops is while.

Syntax :

while (condition)
{
loop body;
}

In the code above example, condition is any expression that returns a Boolean result – true or false. It determines how long the loop body will be repeated and is called the loop condition. In this example the loop body is the programming code executed at each iteration of the loop, i.e. whenever the input condition is true.

Example :

/* Description: Summing the Numbers from 1 to N */ using System; namespace DemoProgramming { class Program { static void Main() { Console.Write("n = "); int n = int.Parse(Console.ReadLine()); int num = 1; int sum = 1; Console.Write("The sum 1"); while (num < n) { num++; sum += num; Console.Write(" + " + num); } Console.WriteLine(" = " + sum); Console.ReadKey(); } } }

Output :