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 does “Count all Occurrences of a Number” mean?

Our task is to find the number of times a key occurs in an array.

For example:

# What does “Count all Occurrences of a Number” mean?

Our task is to find the number of times a key occurs in an array.

For example:

In this lesson, we will learn how to count all occurrences of a key in a given array.

Recursion Fundamentals

Iteration Vs Recursion

Recursion with Numbers

Recursion with Strings

Recursion with Arrays

Recursion with Data Structures

Conclusion

Count all Occurrences of a Number

What does “Count all Occurrences of a Number” mean?