How to call useEffect React Hook on a component mount and unmount

With pure function React Components you're not allowed to use lifecycle methods like componentDidMount or componentWillUnmount.

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    These can be replaced with proper use of useEffect hook introduced in React version 16.8.

    Here is the code that will run exactly once when a component is mounted and exactly once when it's supposed to be unmounted:

    import { useEffect } from "React";
    const ExampleComponent = () => {
      useEffect(() => {
        // Here goes the code you wish to run on mount
        return () => {
          // Here goes the code you wish to run on unmount
      }, []);

    It's crucial to pass an empty array as the second argument of useEffect function call. If you omit it or pass dependencies inside of array it won't work as intended.

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    Szymon Soppa Web Developer
    Szymon Soppa Curiosum Founder & CEO

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