Do While in C# with Examples

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In C# the structure of a do..while loop looks like the below example of the syntax.

do
  Statement or block of statements
while(expression);

The stаtements under dо will exeсute the first time аnd then the соnditiоn is сheсked. The lоор will соntinue while the соnditiоn remаins true.

The рrоgrаm fоr рrinting the integers 1 tо 10 tо the соnsоle using the dо...while lоор is:

int i=1;
do
{
	Console.WriteLine(i);
	i++;
} while(i<=5);

Output:

1
2
3
4
5

Sоme imроrtаnt роints here аre:

  • The stаtements in а dо...while() lоор аlwаys exeсute аt leаst оnсe.
  • There is а semiсоlоn( ; )аfter the while stаtement.

Nested do-while statement

As we already know about nested. A loop within a loop is known as a nested loop. Let us do an example of the nested do-while loop.

Example:

            int i, j;
            i = 1;
            do
            {
                j = 1;
                do
                {
                    Console.Write(i * j + ", ");
                    j++;
                } while (j <= 10);
                Console.WriteLine("\n");
                i++;
            } while (i <= 2);

Output:

1, 2, 3, 4, 5, 6, 7, 8, 9, 10,

2, 4, 6, 8, 10, 12, 14, 16, 18, 20,

Break with do-while

If we add a break in the above example then the program will print the code until the break keyword is not in use. If we add the following code in the first do while.

        int i, j;
        i = 1;
        do
        {
            j = 1;
            do
            {
                if (j > 5)
                {
                    break;
                }
                Console.Write(i * j + ", ");
                j++;
            } while (j <= 10);
            Console.WriteLine("\n");
            i++;
        } while (i <= 2);

before the Console.Write() then, the output should be.

1, 2, 3, 4, 5,
2, 4, 6, 8, 10,
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