CSS in JS is a way of writing css styles in javascript with much more flexiblity and features.

I have already created a video about this on the Cules Coding youtube channel.

Why CSS in JS?

Suppose you have a large-scale application with a lot of components.

Each component has different styles. So you add class names to them. Those class names have some styling.

Now it is easy to mess up with component names like the picture below.

And your whole layout breaks.

How can this problem be solved?

The solution is Scoping CSS. Instead of writing css globally in css styles, what if we can write them inside the component. Then the css styles won't affect other components.

But how do we do something like this?

This is where css-in-js comes into play. Css in js is writing css inside javascript. And we want to write css inside javascript. Now, what css-in-js the library will do is, it will generate a unique class name for the component. And that class will have all the styles.

It will add a unique hash to the class name. Just because the hash will be unique, that's why all the components will have a different style. Now we have Scoping CSS.

How do we write CSS in JS?

There are bunch of libraries out there. Popular ones are:

• Styled Component
• JSS
• Emotion

I like the Styled Component most. You can use whatever you want.

Don't think that all you can do with css-in-js is write scoping Css.

There are a lot of features that those libraries provide us. Like theming, props adaption, extending style, and so on.

And also remember you are writing in JavaScript. That means you can create your functionalities and features. So, don't let yourself restrict within the library features.

To learn more watch the Video.

Shameless Plug

I have made an Xbox landing page clone with React and Styled components. I hope you will enjoy it. Please consider like this video and subscribe to my channel.

That's it for this blog. I have tried to explain things simply. If you get stuck, you can ask me questions.

Contacts

• Email: thatanjan@gmail.com
• LinkedIn: @thatanjan
• Portfolio: anjan
• Github: @thatanjan
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• Twitter: @thatanjan

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