Do While Loop

Do While loop is a variant of the while loop. This loop will always be executed at least once, even if the condition is false, because the code is executed before the condition is tested. The do while loop starts with the do keyword followed by a code and a boolean expression with the while keyword. The do while loop stops repeating when boolean condition inside while turns to false.

Syntax
do {
    // code block to be executed;
}
while (condition);

CODE

EG 1 . Printing 1 to 5 using Do While loop

static void Main(string[] args) {
    int i = 1;
    do {
        Console.WriteLine(i);
        i++;
    } while (i<=5);
}

OUTPUT
1
2
3
4
5

CODE EXPLANATION
In the above code, Initial variable called 'i' will be created and 1 will be stored inside. Now system enters do and execute whatever code we written inside then 'i' got incremented by 1 and condition inside while will be checked. If that condition turns true, again system execute whatever code we written inside do. This operation will be repeated until condition inside while turns to false.


EG 2 . Printing 5 to 1 using Do While loop

static void Main(string[] args) {
    int i = 5;
    do {
        Console.WriteLine(i);
        i--;
    } while (i>=1);
}

OUTPUT
5
4
3
2
1

CODE EXPLANATION
In the above code, Initial variable called 'i' will be created and 5 will be stored inside. Now system enters do and execute whatever code we written inside then 'i' got decremented by 1 and condition inside while will be checked. If that condition turns true, again system execute whatever code we written inside do. This operation will be repeated until condition inside while turns to false.


NOTE
We can create Infinite Do While loop, The syntax for creating Infinite Do While loop is as follows
    do{
        //Code to be executed;
    } while(true);

Exercises
1. Print first 100 even numbers using Do while loop.
2. Find the sum of first 50 natural numbers using Do while loop.


(Click Here, For more exercises)