C# Lesson 3: C# While Loop

What are loops?

Loops are techniques used in programming to repeat a piece of code for a certain amount of time or specific number of repetitions. They are very efficient in minimizing the work load that of repetitive nature. Most common types of loops in C# are for, while, and foreach (for each) loops.
Let us see the while loop in action.
We would like out program to

1. Receive integer input from user on how many times to type a star "*".
2. Type starts with same count as user input.

Let us do it as follows (code in text at the bottom)

Let us now analyze how the code works

• The code receive the user input as a string and convert it into integer.
• The while loop will continue to run as long as its condition(s) are met or true.
• As long as the condition (num>0) is true, it will type a star "*".
• The num-- is self decrement of the integer num by 1. That is, it will decrease from its value each time the loop is executed. When num becomes zero, the while condition is violated and the loop end.

Here is the code in copy-able text

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using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

namespace MyApp1

{

    class Program

    {

        static void Main(string[] args)

        {

            // write to the console window

            Console.Write("Hello, input a number: ");

            // capture user input as string and store in variable called st

            string st =Console.ReadLine();

            int num = Convert.ToInt32(st);

            // while loop

            while(num>0)

            {

                Console.Write("*");

                // decrease number by 1

                num--;

            }

            

            // read line from user to avoid auto-window closure

            Console.ReadLine();

        }

    }

}

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