Master the JavaScript interview with expertly curated questions and solutions. Strategies developed by FAANG engineers help you prep faster, boost confidence, and refine your problem-solving skills.

Master the JavaScript interview by practicing 20 carefully curated interview questions and solutions. These problems will provide the tools you need to tackle any question you find in an interview. Allow ~1 hour per question.

Most questions have multiple solutions presented. All solutions are thoroughly explained and time and space complexity are discussed. A passing familiarity with these ideas is expected. You'll learn how to tackle different types of problems so you can proceed with confidence in your interviews.

These questions go beyond the common problems that we've all seen. FizzBuzz and bubble sort? We start past those.

We'll discuss how to refine algorithms. We'll go over clever, advanced ways of manipulating data that interviewers are looking for. You'll walk away more skilled and confident in your problem solving and interviewing abilities.

This course is taught in ES2015.

Master the JavaScript Interview

# Deep Equals

## Instructions

Write a function that will take in two items of any type. The function should perform a [deep equality](http://adripofjavascript.com/blog/drips/object-equality-in-javascript.html) check.

**Inputs**: Any, Any

**Output**: Boolean

## Hints

- Deep equality is used to check equivalence of objects and arrays. Because of the concept of [value vs. reference](https://www.educative.io/courses/step-up-your-js-a-comprehensive-guide-to-intermediate-javascript/value-vs-reference) in JavaScript, the equality operators (`==`, `===`) can't help us. They'll always return `false` for two different arrays or objects even if they contain the same items.

- If we're comparing objects or arrays, we need to go into them and check that each item is the same. If the item contains other arrays or objects, we need to go into those items as well.

- It's entirely possible to have objects or arrays nested several levels deep. Our function will have to drill all the way down into every object.

- This problem tests several JavaScript concepts:
  
  - Value vs. reference
  - Quirks of different data types such as `NaN` and `null`
  - Use of `typeof`
  - Ability to reuse code

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Introduction

Strings & Arrays

Advanced Strings & Arrays

Algorithms & Data Structures

JavaScript Mastery

Conclusion

Deep Equals

Deep Equals

Instructions

Hints