In this tutorial i will discuss about react hook useEffect. If you are a react js developer then it's a very important for you that you have got clear concept about useEffect. This hook seems like componentDidMount(), componentDidUpdate() and componentWillUnmount().
Remember that
useEffect is a Hook that lets you perform "side effects" in function components, such as data fetching, manual DOM manipulation, and so on...
useEffect accepts a function as argument.
useEffect runs after every render.
See the below code as an example
useEffect accepts a second argument: the dependencies array. It tells React to run the effect function only if one of the dependencies as changed. Or you can pass an empty array ([]) to run it only once.
useEffect(() => {
window.addEventListener("mousedown", eventhandler);
return () => {
window.removeEventListener("mousedown", eventhandler);
};
}, []);
Read also : React Redux Complete Setup Example with Api Call
This above code will render only one time. Hope you got the point.
#react-js #react-hooks