react mounting functional component code example
Example 1: how to use componentdidmount in functional component
useEffect(() => {
if(!props.fetched) {
props.fetchRules();
}
console.log('mount it!');
}, []);
useEffect({
your code here
})
useEffect(() => {
}, [yourDependency]);
useEffect(() => {
return () => {
}
}, [yourDependency]);
Example 2: componentwillunmount hooks
useEffect(() => {
window.addEventListener('mousemove', () => {});
return () => {
window.removeEventListener('mousemove', () => {})
}
}, [])