C# LOOPS

There may be a situation, when you need to execute a block of code several number of times. In general, the statements are executed sequentially: The first statement in a function is executed first, followed by the second, and so on.

Programming languages provide various control structures that allow for more complicated execution paths.

A loop statement allows us to execute a statement or a group of statements multiple times and following is the general from of a loop statement in most of the programming languages:

While Loop

A while loop statement in C# repeatedly executes a target statement as long as a given condition is true

using System;

namespace ConsoleApp1
{
    class Program
    {
        static void Main(string[] args)
        {
            /* local variable definition */
            int a = 10;
            /* while loop execution */
            while (a < 20)
            {
                Console.WriteLine("value of a: {0}", a);
                a++;
            }
            Console.ReadLine();
            //value of a: 10
            //value of a: 11
            //value of a: 12
            //value of a: 13
            //value of a: 14
            //value of a: 15
            //value of a: 16
            //value of a: 17
            //value of a: 18
            //value of a: 19
        }
    }
}

For Loop

A for loop is a repetition control structure that allows you to efficiently write a loop that needs to execute a specific number of times

using System;

namespace ConsoleApp1
{
    class Program
    {
        static void Main(string[] args)
        {
            /* for loop execution */
            for (int a = 10; a < 20; a = a + 1)
            {
                Console.WriteLine("value of a: {0}", a);
            }
            Console.ReadLine();
            //value of a: 10
            //value of a: 11
            //value of a: 12
            //value of a: 13
            //value of a: 14
            //value of a: 15
            //value of a: 16
            //value of a: 17
            //value of a: 18
            //value of a: 19
        }
    }
}

Do…While Loop

Unlike for and while loops, which test the loop condition at the start of the loop, the do…while loop checks its condition at the end of the loop.

A do…while loop is similar to a while loop, except that a do…while loop is guaranteed to execute at least one time

using System;

namespace ConsoleApp1
{
    class Program
    {
        static void Main(string[] args)
        {
            /* local variable definition */
            int a = 10;
            /* do loop execution */
            do
            {
                Console.WriteLine("value of a: {0}", a);
                a = a + 1;
            } while (a < 20);
            Console.ReadLine();
            //value of a: 10
            //value of a: 11
            //value of a: 12
            //value of a: 13
            //value of a: 14
            //value of a: 15
            //value of a: 16
            //value of a: 17
            //value of a: 18
            //value of a: 19
        }
    }
}

Loop Control Statements

Loop control statements change execution from its normal sequence. When execution leaves a scope, all automatic objects that were created in that scope are destroyed.

C# provides the following control statements. Click the following links to check their details

Infinite Loop

A loop becomes infinite loop if a condition never becomes false. The for loop is traditionally used for this purpose. Since none of the three expressions that form the for loop are required, you can make an endless loop by leaving the conditional expression empty

using System;

namespace ConsoleApp1
{
    class Program
    {
        static void Main(string[] args)
        {
            for (; ; )
            {
                Console.WriteLine("Hey! I am Trapped");
            }
        }
    }
}