You know that you need to know Javascript to use React. But how much Javascript should you know? Do you need to learn every concept and master it or can you learn a few basic concepts and then jump into React?

In the long term, the more Javascript you know the better. It is the primary programming language of the web and is crucial fundamental knowledge that will help you understand and use frontend frameworks and tools. Not having a good grasp of Javascript will constantly bother you as you struggle to understand why some code doesn't work.

But realistically, only a subset of Javascript concepts are commonly used with React. So knowing this subset should be sufficient for you to start learning React. If you are not comfortable with Javascript, you might have to go back to it repeatedly when you struggle with certain concepts.

So here are the Javascript concepts that you must know before learning React. This is not a complete list but it should give you a good idea of what you should know.

Concepts that you should definitely know before learning React

If you don't know the following concepts, you will really struggle to understand React.

Concepts that you need to know but could skip for a while

You might be able to start with React without these concepts but not knowing them will limit what you can do.

*Perhaps the most basic way of doing data fetching is with the older XMLHttpRequest API but it is more cumbersome and the Fetch API is more commonly used

Prabashwara Seneviratne

Written by

Prabashwara Seneviratne

Author. Lead frontend developer.