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Thousands of people are learning JavaScript and web development in order to find work. Self-learning frequently results in gaps in people’s grasp of the JavaScript language.

It’s amazing how little programming knowledge is required to create complicated websites. People who create full websites on their own frequently lack a solid understanding of JavaScript’s principles. Avoiding complicated themes and implementing features with basic abilities is rather simple. It’s also simple to build a website using Stack Overflow without knowing what code you’re copying.

Step Up Your JS: A Comprehensive Guide to Intermediate JavaScript is a great resource for mastering JavaScript interviews.


The difficulty is that many tech employers ask questions in their interviews that evaluate your comprehension of JS. When an applicant understands just enough to get by but lacks a thorough understanding of the language, it becomes obvious fast.

In web development interviews, there are a few themes that are usually asked about. This assumes you’re already familiar with the fundamentals, such as loops, functions, and callbacks.


  • Understanding the difference between value and reference — Learn how objects, arrays, and functions are copied and passed into functions. It’s important to understand that the reference is what’s being duplicated. It’s important to remember that primitives are copied and passed by copying the value.
  • Understanding the differences between global, function, and block scope is crucial. Recognize which variables are available in which locations. Learn how the JavaScript engine looks up variables.
  • Understanding that variable and function declarations are hoisted to the top of their accessible scope is important. It’s important to remember that function expressions aren’t hoisted.
  • Closures — Keep in mind that a function keeps access to the scope in which it was created. Know what data hiding, memoization, and dynamic function generation are possible with this.
  • this — Be aware of the binding’s rules. Understand how it works, how to calculate what it will equal in a function, and why it is useful.
  • new — Understand how it relates to OO programming. Find out what occurs when you call a function with new. Understand how the object created with new inherits from the prototype property of the function.
  • Know how each of these functions works: call, bind, and apply. Know how to put them to good use. Know what they’re going to do with this.
  • Inheritance in JavaScript works through the [[Prototype]] chain, which you should be aware of. Understand how to set up inheritance using functions and objects, as well as how new can assist us in doing so. Understand the meaning of the proto and prototype attributes.
  • Understand the event loop in asynchronous JS. Recognize how your browser handles user input, web requests, and events in general. Recognize asynchronous code and correctly implement it. Understand the asynchronous and single-threaded nature of JavaScript.
  • Higher Order Functions – Recognize that functions in JavaScript are first-class objects and what that entails. It’s important to understand that returning a function from another function is completely lawful. Recognize the methods that closures and higher order functions enable us to employ.

More Resources

If the links provided aren’t enough, there are a plethora of more resources available to assist you in learning these ideas.

To help developers expand their skills, I wrote Step Up Your JS: A Comprehensive Guide to Intermediate JavaScript. It covers all of these topics, as well as many others.

Here are some materials that I have read or watched and can suggest.

Good luck.

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A bright, talented, ambitious and self-motivated 💻 Freelancer, ⌨ Programmer, JavaScript and Typescript lover 📍

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