W1154 For Loop

Within these castle walls be forged Mavens of Computer Science ...

— Merlin, The Coder

Roller Coaster Loop

Prerequisites

• W1151 Conditional and Flow Chart
• W1152 While Loop
• W1153 Repeat-While Loop

Introduction

Loops are the general term for executing a defined segment of code zero or more times, where the number of iterations is dependent upon test conditions within the loop. The for loop is a construct which enables us to execute a segment of code a defined number of times. It is thus the most appropriate choice when we know in advance how to calculate the number of iterations prior to beginning the loop. While this construct is not strictly necessary, it provides syntactic sugar by clarifying intent.

For Loops

for loops execute for a defined count of iterations, as such, the test condition is implied within the definition. Through each iteration, a loop control variable is adjusted toward its final goal. When that goal is reached, the loop exits.