8 JavaScript Interview Topics

As more people are learning JavaScript and more jobs using JavaScript open, it’s important to be prepared with some of the basic/hot topics asked during interviews. These aren’t the only topics you should be studying, but these topics can certainly be good starting points for a lot of people.

Let’s go over the 8 topics and couple of things that you should know for each topic:

Topics

1. Scope
2. Hoisting
3. Closure
4. this
5. Prototypal Inheritance
6. Promise
7. Pass by Value & Reference
8. Higher-Order Function

Scope

• Difference between global scope and block scope
• Know which variable is available and where

Hoisting

• Remember that variable and function declaration get hoisted
• Different ways to declare a variable and which one leads to variable hoisting (var, let, and const )

Closure

• Prepare to define closure
• Advantages of using closure (eg. hiding data)

this

• Know what context is
• How to use this keyword in your code
• Good to how you can use it in for binding context

Prototypal Inheritance

• Remember that JavaScript uses prototypal inheritance
• How to create your own prototype chain using objects
• Good to know the difference between prototypal inheritance and classical inheritance

Promise

• Advantages of using promises
• How to implement your own promise

Pass by Value & Reference

• Difference between pass by value and pass by reference
• Primitive type variables are copied

Higher-Order Function

• Know what function being first-class object in JavaScript means
• JavaScript allows function to be passed an argument to another function

Certainly check out the references below to solidify your basics of JavaScript for the interviews!

References

Basics of JavaScript:

Variable: https://readmedium.com/basics-of-javascript-variable-3eb6f4f0af18

Data Types: https://readmedium.com/basics-of-javascript-data-types-385bab24b51

JavaScript Fundamentals

Prototypal Inheritance: https://readmedium.com/javascript-fundamental-prototypal-inheritance-9153ab434aae

JavaScript Array Methods

Array Methods Cheatsheet: https://readmedium.com/javascript-array-methods-cheatsheet-633f761ac250

Sorting Algorithms

Merge Sort in JavaScript: https://readmedium.com/javascript-merge-sort-3205891ac060

Additional:

Github: https://github.com/yeb9925/sorting-algorithms

What You Should Know Latest JavaScript: https://hackernoon.com/why-you-should-know-latest-javascript-4a72a55fca5d