Programming Fundamentals/Iteration Control Structures

Overview
In iteration control structures, a statement or block is executed until the program reaches a certain state, or operations have been applied to every element of a collection. This is usually expressed with keywords such as,  ,  , or.

Discussion
The basic attribute of an iteration control structure is to be able to repeat some lines of code. The visual display of iteration creates a circular loop pattern when flowcharted, thus the word “loop” is associated with iteration control structures. Iteration can be accomplished with "test before" loops, "test after" loops, and counting loops. A question using Boolean concepts usually controls how often the loop will execute.

Pseudocode: Iteration (Repetition) Control Structures
While Loop count assigned zero While count < 5 Display "I love computers!" Increment count End Do-While Loop count assigned five Do    Display "Blast off is soon!" Decrement count While count > zero Repeat-Until Loop count assigned five Repeat Display "Blast off is soon!" Decrement count Until count < one For Loop For x starts at 0, x < 5, increment x    Display "Are we having fun?" End