Do While loop

The Do While loop is similar to While loop. The main difference is that Do While checks the condition after it executes the body. It executes the body at least once.

Let's write a program that reads a number from user.
If the entered number is not positive, we ask the user to enter a number again. Steps:

• declare x: Integer
• add a Do While block with condition x <= 0
• input x in the Do While body (arrow pointing from circle to the Do While diamond)

We read it like this: "Enter number x, as long as it is less than or equal to zero". The Do While loop will loop as long as the x <= 0. When the user enters a x > 0 the loop will exit, and the program will continue its execution.

Run the program and try various inputs: 1, 17, -55, 6, 0.