Learn React: Hooks Cheatsheet | Codecademy

const [showDialog, setShowDialog] = useState(true);

<DisclaimerModal
     text='...'
     showDialog={showDialog}
     handleAccept={() => setShowDialog(false)}
     handleDecline={() => setShowDialog(false)}
/>

const App = () => {
  return(
    <Router>
      <Routes>
        <Route path="/component1" element={<Component1 />} />
		<Route path="/component2/:data" element={<Component2 />} />
      </Routes>
    </Router>
  )
}
const Component2 = () => {
  const { data } = useParams();
  return(
    <div>
      <h2>The data is: {data}</h2>
    </div>
  )
}

//HTML
<div class='dropdown'>
          <Link id='product' className='every' to='/products'>OUR PRODUCTS</Link>
           <div class='dropdown-content'>
            <Link to='autocadd'>AutoCadd</Link>
            <Link to='techset'>Techset</Link>
            <Link to='Endorse'>Endorse</Link>
           </div>
          </div>

//CSS

.dropdown{
    position: relative;
    display: inline-block;
}
.dropdown-content{
    display: none;
    position: absolute;
    background-color: #f1f1f1;
    min-width: 160px;
    box-shadow: 0px 8px 16px 0px rgba(0,0,0,0.2);
    z-index: 1;
}

.dropdown-content>*{
 color: black;
 padding: 12px 6px;
text-decoration: none;
 display: block;
}

.dropdown:hover .dropdown-content{
    display: block;
}
.dropdown-content>*:hover{
    background-color: #ddd;
}

setTheme = () => {
    let element = document.getElementById('doc');
    // element.setAttribute('class','dark');
    element.classList.toggle('dark');
}

  render() {
    return (
      <div id='doc' class='light'>
        <h1>Hey</h1>
        <button id='btn' onClick={this.setTheme}>Click</button>
      </div>
    )
  }

import { useState, useEffect } from "react";

function getValue(key, initailValue) {
  const storedValue = JSON.parse(localStorage.getItem(key));
  if (storedValue) return storedValue;

  if (initailValue instanceof Function) return initailValue();
  return initailValue;
}

export default function useLocalStorage(key, initailValue) {
  const [value, setValue] = useState(() => {
    return getValue(key, initailValue);
  });

  useEffect(() => {
    localStorage.setItem(key, JSON.stringify(value));
  }, [value]);

  return [value, setValue];
}

import React from "react";

class Clock extends React.Component {
  constructor(props) {      //Constructor is  called when root is rendered
    super(props);
    this.state = { date: new Date() }; //intializes this.state with current time
  }


  componentDidMount() { //React lifecycle method, is been called when clock output is inserted in the DOM
    this.timerID = setInterval(
        () => this.tick(),
        1000
    )           //Here class component asks the browser to set up a timer to call the tick() method once a second
  }

  tick(){               
    this.setState({         //calling setState method with an object containing the current time
        date: new Date()
    });                     //setState method updates the current time
}

  componentWillUnmount() {      // Incase if clock component is ever removed from the DOM , react call this lifecycle method so the timer is stopped.
    clearInterval(this.timerID)
  }
  


  render() {
    return (
      <div>
        <h1>Hello, world!</h1>
        <h2>It is {this.state.date.toLocaleTimeString()}.</h2>
      </div>
    );
  }
}

export default Clock;

import React from "react";

class Clock extends React.Component {
  constructor(props) {      //Constructor is  called when root is rendered
    super(props);
    this.state = { date: new Date() }; //intializes this.state with current time
  }


  componentDidMount() { //React lifecycle method, is been called when clock output is inserted in the DOM
    this.timerID = setInterval(
        () => this.tick(),
        1000
    )           //Here class component asks the browser to set up a timer to call the tick() method once a second
  }

  tick(){               
    this.setState({         //calling setState method with an object containing the current time
        date: new Date()
    });                     //setState method updates the current time
}

  componentWillUnmount() {      // Incase if clock component is ever removed from the DOM , react call this lifecycle method so the timer is stopped.
    clearInterval(this.timerID)
  }
  


  render() {
    return (
      <div>
        <h1>Hello, world!</h1>
        <h2>It is {this.state.date.toLocaleTimeString()}.</h2>
      </div>
    );
  }
}

export default Clock;

import React from "react";

class Clock extends React.Component {
  constructor(props) {      //Constructor is  called when root is rendered
    super(props);
    this.state = { date: new Date() }; //intializes this.state with current time
  }


  componentDidMount() { //React lifecycle method, is been called when clock output is inserted in the DOM
    this.timerID = setInterval(
        () => this.tick(),
        1000
    )           //Here class component asks the browser to set up a timer to call the tick() method once a second
  }

  tick(){               
    this.setState({         //calling setState method with an object containing the current time
        date: new Date()
    });                     //setState method updates the current time
}

  componentWillUnmount() {      // Incase if clock component is ever removed from the DOM , react call this lifecycle method so the timer is stopped.
    clearInterval(this.timerID)
  }
  


  render() {
    return (
      <div>
        <h1>Hello, world!</h1>
        <h2>It is {this.state.date.toLocaleTimeString()}.</h2>
      </div>
    );
  }
}

export default Clock;

import React from "react";

class Clock extends React.Component {
  constructor(props) {      //Constructor is  called when root is rendered
    super(props);
    this.state = { date: new Date() }; //intializes this.state with current time
  }


  componentDidMount() { //React lifecycle method, is been called when clock output is inserted in the DOM
    this.timerID = setInterval(
        () => this.tick(),
        1000
    )           //Here class component asks the browser to set up a timer to call the tick() method once a second
  }

  tick(){               
    this.setState({         //calling setState method with an object containing the current time
        date: new Date()
    });                     //setState method updates the current time
}

  componentWillUnmount() {      // Incase if clock component is ever removed from the DOM , react call this lifecycle method so the timer is stopped.
    clearInterval(this.timerID)
  }
  


  render() {
    return (
      <div>
        <h1>Hello, world!</h1>
        <h2>It is {this.state.date.toLocaleTimeString()}.</h2>
      </div>
    );
  }
}

export default Clock;

import React from "react";

class Clock extends React.Component {
  constructor(props) {      //Constructor is  called when root is rendered
    super(props);
    this.state = { date: new Date() }; //intializes this.state with current time
  }


  componentDidMount() { //React lifecycle method, is been called when clock output is inserted in the DOM
    this.timerID = setInterval(
        () => this.tick(),
        1000
    )           //Here class component asks the browser to set up a timer to call the tick() method once a second
  }

  tick(){               
    this.setState({         //calling setState method with an object containing the current time
        date: new Date()
    });                     //setState method updates the current time
}

  componentWillUnmount() {      // Incase if clock component is ever removed from the DOM , react call this lifecycle method so the timer is stopped.
    clearInterval(this.timerID)
  }
  


  render() {
    return (
      <div>
        <h1>Hello, world!</h1>
        <h2>It is {this.state.date.toLocaleTimeString()}.</h2>
      </div>
    );
  }
}

export default Clock;

import React from "react";

class Clock extends React.Component {
  constructor(props) {      //Constructor is  called when root is rendered
    super(props);
    this.state = { date: new Date() }; //intializes this.state with current time
  }


  componentDidMount() { //React lifecycle method, is been called when clock output is inserted in the DOM
    this.timerID = setInterval(
        () => this.tick(),
        1000
    )           //Here class component asks the browser to set up a timer to call the tick() method once a second
  }

  tick(){               
    this.setState({         //calling setState method with an object containing the current time
        date: new Date()
    });                     //setState method updates the current time
}

  componentWillUnmount() {      // Incase if clock component is ever removed from the DOM , react call this lifecycle method so the timer is stopped.
    clearInterval(this.timerID)
  }
  


  render() {
    return (
      <div>
        <h1>Hello, world!</h1>
        <h2>It is {this.state.date.toLocaleTimeString()}.</h2>
      </div>
    );
  }
}

export default Clock;

import React from "react";

class Clock extends React.Component {
  constructor(props) {      //Constructor is  called when root is rendered
    super(props);
    this.state = { date: new Date() }; //intializes this.state with current time
  }


  componentDidMount() { //React lifecycle method, is been called when clock output is inserted in the DOM
    this.timerID = setInterval(
        () => this.tick(),
        1000
    )           //Here class component asks the browser to set up a timer to call the tick() method once a second
  }

  tick(){               
    this.setState({         //calling setState method with an object containing the current time
        date: new Date()
    });                     //setState method updates the current time
}

  componentWillUnmount() {      // Incase if clock component is ever removed from the DOM , react call this lifecycle method so the timer is stopped.
    clearInterval(this.timerID)
  }
  


  render() {
    return (
      <div>
        <h1>Hello, world!</h1>
        <h2>It is {this.state.date.toLocaleTimeString()}.</h2>
      </div>
    );
  }
}

export default Clock;

npm install react-bootstrap bootstrap@5.1.3

    <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.1.1/css/all.min.css" integrity="sha512-KfkfwYDsLkIlwQp6LFnl8zNdLGxu9YAA1QvwINks4PhcElQSvqcyVLLD9aMhXd13uQjoXtEKNosOWaZqXgel0g==" crossorigin="anonymous" referrerpolicy="no-referrer" />

import {useState} from 'react';

export default function App() {
  const initialState = [
    {id: 1, name: 'Alice'},
    {id: 2, name: 'Bob'},
  ];
  const [employees, setEmployees] = useState(initialState);

  const handleClick = () => {
    // 👇️ push object to end of state array
    setEmployees(current => [...current, {id: 3, name: 'Carl'}]);

    // 👇️ spread an array of objects into the state array
    // setEmployees(current => [
    //   ...current,
    //   ...[
    //     {id: 3, name: 'Carl'},
    //     {id: 4, name: 'Delilah'},
    //   ],
    // ]);

    // 👇️ push object to beginning of state array
    // setEmployees(current => [{id: 3, name: 'Zoey'}, ...current]);
  };

  return (
    <div>
      <div>
        <button onClick={handleClick}>Push to state array</button>
      </div>

      {employees.map((element, index) => {
        return (
          <div key={index}>
            <h2>{element.name}</h2>
          </div>
        );
      })}
    </div>
  );
}