Useref react

UseRef

/*
	A common use case is to access a child imperatively: 
*/

function TextInputWithFocusButton() {
    const inputEl = useRef(null);
  const onButtonClick = () => {
    // `current` points to the mounted text input element
    inputEl.current.focus();
  };
  return (
    <>
      <input ref={inputEl} type="text" />
      <button onClick={onButtonClick}>Focus the input</button>
    </>
  );
}

Source: reactjs.org

UseReducer

const initialState = {count: 0};

function reducer(state, action) {
  switch (action.type) {
    case 'increment':
      return {count: state.count + 1};
    case 'decrement':
      return {count: state.count - 1};
    default:
      throw new Error();
  }
}

function Counter() {
  const [state, dispatch] = useReducer(reducer, initialState);
  return (
    <>
      Count: {state.count}
      <button onClick={() => dispatch({type: 'decrement'})}>-</button>
      <button onClick={() => dispatch({type: 'increment'})}>+</button>
    </>
  );
}

Source: reactjs.org

What does useref do react

const refContainer = useRef(initialValue);
//useRef returns a mutable ref object whose .current property is initialized to the passed argument (initialValue). 
//The returned object will persist for the full lifetime of the component.

Source: reactjs.org

Useref react

function TextInputWithFocusButton() {
    const inputEl = useRef(null);
  const onButtonClick = () => {
    // `current` points to the mounted text input element
    inputEl.current.focus();
  };
  return (
    <>
      <input ref={inputEl} type="text" />
      <button onClick={onButtonClick}>Focus the input</button>
    </>
  );
}

Source: reactjs.org

Useref

  const inputEl = useRef(null);

Useref in functional component

import React, { useRef } from 'react';function TextInputWithFocusButton() {
    const inputEl = useRef(null);
  const onButtonClick = () => {
    // `current` points to the mounted text input element
    inputEl.current.focus();
  };
  return (
    <>
      <input ref={inputEl} type="text" />
      <button onClick={onButtonClick}>Focus the input</button>
    </>
  );
}

Source: reactjs.org

Similar codes

0 vote296 views1 answer
React native run real device
Javascript React
0 vote337 views1 answer
Props with ternary in react
Javascript React
8 votes305 views1 answer
React-fragment
Javascript React
2 votes315 views4 answers
Multiple export in react
Javascript React
18 votes266 views6 answers
Add svg in react
Javascript React
0 vote352 views1 answer
React native listview date separator site:stackoverflow.com
Javascript React
110 votes330 views2 answers
Create react js app
Javascript React
3 votes314 views1 answer
React pass props to children
Javascript React
29 votes292 views2 answers
React or vue
Javascript React
0 vote315 views1 answer
React time input
Javascript React