Introduction

What is a Loop?

A loop is categorized as a control structure that is used to execute a set of operations repeatedly for a specific number of iterations.

Like conditionals, loops play a role in controlling the flow of the program.

A big benefit of using loops is that it saves time. If a piece of code needs to run 300 times, we wouldn’t need to write it for all those instances. A loop does it for us.

Loops are most commonly used to traverse an array or list which is discussed in the next section. In principle, moving through an array element by element is an iterative process, i.e., we must traverse the list step by step repeatedly. Hence, a loop fits such a process perfectly.

Reason’s Approach

Reason supports two popular loop structures:

1. for loop
2. while loop

We’ll discuss their unique behavior and features in the coming lessons.

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Let’s get started with the for loop.