using useeffect code example

Example 1: useeffect umnount

useEffect(() => {
    return () => {
      console.log("cleaned up");
    };
  }, []);

Example 2: useeffect with cleanup

useEffect(() => {
	//your code goes here
    return () => {
      //your cleanup code codes here
    };
  },[]);

Example 3: componentdidupdate in hooks

const App = props => {
  const didMountRef = useRef(false)
  useEffect(() => {
    if (didMountRef.current) {
      doStuff()
    } else didMountRef.current = true
  }
}

Example 4: 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 5: useEffect

import React, { useState, useEffect } from 'react';

function Example() {
  const [count, setCount] = useState(0);

  // Similar to componentDidMount and componentDidUpdate:
  useEffect(() => {
    // Update the document title using the browser API
    document.title = `You clicked ${count} times`;
  });

  return (
    <div>
      <p>You clicked {count} times</p>
      <button onClick={() => setCount(count + 1)}>
        Click me
      </button>
    </div>
  );
}

Example 6: react useeffect

import React, { useEffect } from 'react';
	
	const [data,setData]=useState()
    useEffect(() => {
        fetch(`put your url/api request in here`)
        .then(res=>res.json())
        .then(json => setData(json))
    },[])