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

# Problem Statement
Implement a function that takes an array `arr`, a `testVariable` containing the number to search and `currentIndex` containing the starting index as parameters and outputs the index of the first occurrence of `testVariable` in `arr`. If `testVariable` is not found in `arr` return $-1$.

We want to search for a `targetNumber` from index `currentIndex` to the end of the array.

> Try to implement your solution recursively.

## Input
1. A variable `arr` that contains the array on which searching is to be performed.
2. A variable `testVariable` that contains the number that needs to be searched.
3. A variable `currentIndex` that contains the starting index of the `arr` array.

## Output
Index of the first occurrence of `testVariable` in `arr`.

## Sample Input
```javascript
arr = [9, 8, 1, 8, 1, 7];
testVariable = 1;
currentIndex = 0;
```

## Sample Output
```
2
```

## Try it Yourself
Try this challenge yourself before examining the solution. Good luck!



Given an array, find the first occurrence of a given target number.

Recursion Fundamentals

Iteration Vs Recursion

Recursion with Numbers

Recursion with Strings

Recursion with Arrays

Recursion with Data Structures

Conclusion

Challenge 2: Search the First Occurrence of a Number

Problem Statement