React - How to add the Classname onHover

In this tutorial, we are going to learn about how to add the clasname to a element on hover in react.

Consider, we have the following component in our react app:

import React from 'react';

function Home(){
    return (
        <div>
          <h1>Welcome to my blog</h1>
        </div>
    )
}

export default Home;

To add the classname of a element on hover, add the onMouseOver and onMouseOut event handler to it and change the classname conditionally whenever a element is hovered.

Here is an example:

import React, { useState } from "react";

function Home() {
  const [active, setActive] = useState(false);

  const handleMouseOver = () => {
    setActive(true);
  };

  const handleMouseOut = () => {
    setActive(false);
  };


  return (
    <div>
       <h1
         onMouseOver={handleMouseOver}
         onMouseOut ={handleMouseOut}
         className={{active ? "container" : "box" }}
       >Welcome to my blog</h1>
    </div>
  );
}

export default Home;

In the example above, we added a handleMouseOver and handleMouseOut event handlers to the onMouseOver, onMouseOut props and state active to the className property.

So, whenever a h1 element is hoverd it runs the handleMouseOver function and changes the active state from false to true and adds the container classname to it.

Whenever a mouse is moved away from the h1 element it adds the box classname to it.

Based on the active state we are changing the h1 element classname using ternary expression.

{{active ? "container" : "box" }}

If active is false it chooses the box class, if its true it chooses the container class.

References

• onMouseOver

• onMouseOut