The ultimate guide to recursion interviews in JavaScript. Developed by FAANG engineers. Practice with real-world interview questions and get interview-ready in just a few hours.

If you’ve ever struggled with solving problems using recursion, or if you have to brush up your skills for an interview, this course is for you.

We'll start with the basics of what recursion is and why it’s important before diving into practicing solving actual questions. You’ll have access to detailed explanations and visualizations for each problem to help you along the way. 

By the time you have completed this course, you’ll be able to use all the concepts to solve complex real-world problems. We hope that through practicing recursion, you will be able to ace all recursion related questions in interviews at top tech companies.

Recursion for Coding Interviews in JavaScript

## What is the modulo operation?

The **modulo operation** (abbreviated as **mod**) returns the *remainder* when a number is divided by another. The symbol for `mod` is `%`.

> The number being divided is called the **dividend**, and the number that divides is called the **divisor**.

The illustration below represents the concept of remainders using basic division:

# What is the modulo operation?

The **modulo operation** (abbreviated as **mod**) returns the *remainder* when a number is divided by another. The symbol for `mod` is `%`.

> The number being divided is called the **dividend**, and the number that divides is called the **divisor**.

The illustration below represents the concept of remainders using basic division:

In this lesson, we'll learn about the modulo operation and how to implement it using recursion.

Recursion Fundamentals

Iteration Vs Recursion

Recursion with Numbers

Recursion with Strings

Recursion with Arrays

Recursion with Data Structures

Conclusion

Modulus

What is the modulo operation?