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

## Instructions

A matrix in JavaScript can be represented as an array of arrays. For example, here is a 3 x 3 matrix:

    [[1, 2, 3],
     [4, 5, 6],
     [7, 8, 9]]

Write a function that takes a matrix as input and returns a new matrix. This new matrix should represent the original matrix rotated 90 degrees clockwise. The original matrix should be unchanged. This function should work for both square and rectangular matrixes.

**Input**: Array of Arrays of Numbers

**Output**: Array of Arrays of Numbers

## Example

When given the matrix above as input, the output should be:

    [[7, 4, 1],
     [8, 5, 2],
     [9, 6, 3]]

## Hints

- We'll need to start by creating a new, empty matrix.
- The new matrix dimensions will need to be switched, e.g. 2 x 3 becomes 3 x 2.
- We'll need to process every item.

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We'll learn how to work with a matrix in JavaScript and how to efficiently manipulate it. We'll cover a couple of clever tricks that can make our lives a lot easier by allowing us to reuse code.

Introduction

Strings & Arrays

Advanced Strings & Arrays

Algorithms & Data Structures

JavaScript Mastery

Conclusion

Rotate Matrix

Rotate Matrix

Instructions

Example