About This Course

This lesson describes what the course entails and who it is for.

We'll cover the following

What is this course about? #

JavaScript interviews are not the easiest. How should you prepare? Where should you start? These are some common questions that anyone who is beginning interview preparation has. There is a wide range of possibilities for the questions asked during the interview, including questions about your past experiences with technologies.

This course is a guide for those preparing for frontend interviews. It is not for complete newbies; hence, it assumes you are familiar with the fundamentals of JavaScript. The course prepares you to take baby steps towards frontend interview preparation by focusing on the most fundamental concepts of the language that interviewers expect candidates to know. The course does not test data structures or algorithms in JS. It focuses on language concepts only. The topics tested include:

  • basics: functions, hoisting, arrow functions, rest/spread syntax, closure, setTimeout, bind function, destructuring syntax, and IIFE.

  • type coercion: typeof and instanceof operators, and prototype.toString.

  • event handling: event bubbling, capturing, and delegation

  • asynchronous callbacks: callbacks, promises, and async/await

  • OPP in Javascript: prototypes, ES5 and ES6 versions of inheritance, and mixins.

  • functional programming: currying, pure/impure functions, higher-order functions, shallow copy, and deep copy

  • security: strict mode and the same-origin policy.

  • DOM basics.

This course has plenty of challenges and quizzes. Some of the questions are commonly asked during the interviews; others are to help you practice a concept so that you can answer any hard or tricky questions related to it. Every quiz is followed by a note explaining if the question can be asked of a person with entry-level, mid-level, junior-level, senior-level, or expert-level experience. However, remember that a basic understanding of all these concepts is required in all interviews.


You’ll start the course with a self-evaluation. The next lesson has a quiz testing the very basics of the JavaScript language. This will help you decide if you need to review some concepts first or if you want to jump right into the challenges.