React useState and useReducer

Snippets

// this will return an array [100,f]
// basically this returns a state and a function to update the state
// we can destructure the array and get the state and the function
const [state, setState] = useState(100);

// you pass function in useState it will set the initial value to what function returns
// it is useful when you use computationaly high task as initial state
const [state, setState] = useState(() => {
  console.log("initial state");
  return 100;
});

onClick={() => {
  // here value in the props is the state
  setState((value) => {
    //you can use this method when you need to update the state from a previous state value
    return value + 1;
  });
}}

Snippets​

Snippets