state example in react

Example 1: state with react functions

import React, { useState } from 'react';

function Example() {
  // Declare a new state variable, which we'll call "count"
  const [count, setCount] = useState(0);

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

Example 2: set state

class App extends React.Component {

state = { count: 0 }

handleIncrement = () => {
  this.setState({ count: this.state.count + 1 })
}

handleDecrement = () => {
  this.setState({ count: this.state.count - 1 })
}
  render() {
    return (
      <div>
        <div>
          {this.state.count}
        </div>
        <button onClick={this.handleIncrement}>Increment by 1</button>
        <button onClick={this.handleDecrement}>Decrement by 1</button>
      </div>
    )
  }
}

Example 3: setting react state with produce immer

//Initialising State
const [filters, setFilters] = useState({});


//Setting State

setFilters((filters) => (
        produce(filters, draftFilters => {
          if (param[0] === 'page') {
            draftFilters.page = parseInt(param[1], 10)
          }
          if (param[0] === 'per_page') {
            draftFilters.perPage = parseInt(param[1], 10)
          }
        })
      ));