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 `testVariable` containing opening `(` and closing parenthesis `)` and determines whether or not the brackets in the array are balanced. The function also takes `startIndex = 0` and `currentIndex = 0` as parameters.

### What does "Balanced Parenthesis" Mean?
**Balanced parentheses** mean that each opening bracket `(` has a corresponding closing bracket `)`. Also, the pairs of parentheses are *properly nested*. 

Consider the following correctly balanced parentheses:

$$()$$
$$(())$$
$$(())()$$
$$((()))((()))$$

Now take a look at some incorrectly balanced parentheses:

$$($$
$$)()($$
$$((()()()()$$
$$((())))((((()$$

### Input

An array `testVariable` containing opening and closing parentheses.

### Output
`true` if the parentheses in the input array are balanced. `false` if the parentheses in the input array are imbalanced.

### Sample Input
```javascript
testVariable = ["(", ")", "(", ")"]
```

### Sample Output
```javascript
true
```

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

# Problem Statement
Implement a function that takes an array `testVariable` containing opening `(` and closing parenthesis `)` and determines whether or not the brackets in the array are balanced. The function also takes `startIndex = 0` and `currentIndex = 0` as parameters.

## What does "Balanced Parenthesis" Mean?
**Balanced parentheses** mean that each opening bracket `(` has a corresponding closing bracket `)`. Also, the pairs of parentheses are *properly nested*. 

Consider the following correctly balanced parentheses:

$$()$$
$$(())$$
$$(())()$$
$$((()))((()))$$

Now take a look at some incorrectly balanced parentheses:

$$($$
$$)()($$
$$((()()()()$$
$$((())))((((()$$

## Input

An array `testVariable` containing opening and closing parentheses.

## Output
`true` if the parentheses in the input array are balanced. `false` if the parentheses in the input array are imbalanced.

## Sample Input
```javascript
testVariable = ["(", ")", "(", ")"]
```

## Sample Output
```javascript
true
```

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

Given an array that contains opening and closing parentheses, check whether or not the opening and closing parentheses are balanced.

Recursion Fundamentals

Iteration Vs Recursion

Recursion with Numbers

Recursion with Strings

Recursion with Arrays

Recursion with Data Structures

Conclusion

Challenge 2: Balance Parenthesis

Problem Statement

What does “Balanced Parenthesis” Mean?