How to avoid re-rendering when i pass an object as prop to child component?

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I have parent component with multiple child components. Different types of data will be passed to child components after getting data from api. Some of the components will get object as a prop. I am trying to avoid rerenders in that component. Even if the data is same it is rerendering. How can i avoid this rerenders?

const Parent = () => {
  const [childData, setChildData] = useState(null);
  
  useEffect(() => {
    const data = getChildData();
    setChildData(data);
  }, [])

  return (
      <Child data={childData}/>
  );
};

const Child = React.memo((props) => {
  const {name, email} = props.data;
  return (
      <div>
        <p>Name: {name}</p>
        <p>Email: {email}</p>
      </div>
  );
});

Answer

As per React Official Docs, By default React will only shallowly compare complex objects in the props object. If you want control over the comparison, you can also provide a custom comparison function as the second argument. https://reactjs.org/docs/react-api.html#reactmemo. Here is an example.

const Parent = () => {
    const [childData, setChildData] = useState(null);

    useEffect(() => {
        const data = getChildData();
        setChildData(data);
    }, [])

    return (
        <Child data={childData} />
    );
};

function areEqual(prevProps, nextProps) {
    return prevProps.name == nextProps.name && prevProps.email == nextProps.email;
}
const Child = React.memo((props) => {
    const { name, email } = props.data;
    return (
        <div>
            <p>Name: {name}</p>
            <p>Email: {email}</p>
        </div>
    );
}, areEqual);



Source: stackoverflow