Repeat with do while

You can also repeat code using a do while loop. This works like the while loop, but the condition appears after the loop’s instructions. This means that you have to run these instructions at least once.

The do while loop…

• runs its instructions and then checks its condition and either goes back the to the start of its instructions, or continues to the next instruction after the loop.
• runs the body 1 or more times.
• is less common than the while loop.

Tip

As with the while loop, remember that the instructions still run in sequence. So the condition is only checked once at the end of each loop.

While or do while

Most of the time you will use a while loop, but in some cases the do while can be useful. If you are sure the code must run at least once, then you can consider a do while loop.

Example

The following example shows a menu in the terminal. This is one place where a do while loop can work well.

using static SplashKitSDK.SplashKit;
using static System.Convert;

string line;

do
{
    WriteLine("1: Say hello");
    WriteLine("2: ...");
    WriteLine("3: Quit");

    line = ReadLine();

    switch(line)
    {
        case "1":
            WriteLine("Hello!");
            break;
        case "2":
            WriteLine("...");
            break;
        case "3":
            break;
        default:
            WriteLine("Please enter a menu option");
            break;
    }
} while(line != "3");