Iteration vs Recursion — What’s the Difference?

With having relatively similar concepts, iteration and recursion are often used interchangeably. At the top level, both iteration and recursion repeatedly execute a set of instructions. The primary difference lies in how this execution is structured. In addition, there are other key differences that we will also cover in this post.

Iteration

Iteration uses a repetition structure; until a condition is met (or the condition is false), the set of instructions are looped through over again.

Iteration example code

Recursion

Recursion uses a selection structure; it is a process that is applied to a function, achieves repetition through repeated method calls, and continues until a base case is recognized. The purpose of recursion is to simplify the computation.

Recursion example code

Additional Key Differences

• Iteration is faster because it doesn’t use the stack where recursion maintains the stack.
• Infinite recursion can crash the system, whereas infinite iteration uses CPU cycles repeatedly.
• Iteration uses more code than recursion.
• Iteration uses less memory.

I hope you found this helpful!

Resources:

Tech Differences — Difference Between Recursion and Iteration