react what is useeffect code example
Example 1: useeffect with cleanup
useEffect(() => {
return () => {
};
},[]);
Example 2: useeffect
function App() {
const [count, setCount] = useState(0);
useEffect(() => {
longResolve().then(() => {
alert(count);
});
}, []);
return (
<div>
<button
onClick={() => {
setCount(count + 1);
}}
>
Count: {count}
</button>
</div>
);
}
Example 3: react useEffect
import React, { useState, useEffect } from 'react';
function Example() {
const [count, setCount] = useState(0);
return (
<div>
<p>You clicked {count} times</p>
<button onClick={() => setCount(count + 1)}>
Click me
</button>
</div>
);
}
Example 4: usestate
const [count, setCount] = useState(0);