Why isn't the second argument being called inside React.memo()?

Question

React

I was expecting that after the component is clicked, the check function inside React.memo() will be executed and it will not update. But this function is not executed, and I can't figure out what's wrong.

const Item = styled.div`
  //styles
`;

const Cell = (props) => {
  const [isSelected, setIsSelected] = useState(false);

  return (
    <Item onClick={() => setIsSelected(!isSelected)} status={{key: isSelected}} />
  )
}

const check = (prevProps, props) => prevProps === props;

const memoComp = React.memo(Cell, check)

Answer 1

We open the documentation and see that

React.memo only affects prop changes. If a functional component is wrapped in React.memo and uses useState , useReducer , or useContext , it will re-render when the state or context changes.