Inline style jsx / react

const [ user, setUser ] = useState(JSON.parse(localStorage.getItem('profile'))); //convert to object

const logout = () =>{
        dispatch({type: 'LOGOUT'});
        history.push("/");
        setUser(null);
    }

    useEffect(()=>{
        const token = user?.token;

        //JWT check if token expired
        if(token){
            const decodedToken = decode(token)
            if(decodedToken.exp*1000 < newDate().getTime()) logout();
        }
        setUser(JSON.parse(localStorage.getItem('profile')))
    },[location])

const [animateHeader, setAnimateHeader] = useState(false)

useEffect(() => {
  const listener = () =>
  window.scrollY > 140 ? setAnimateHeader(true) : setAnimateHeader(false)
  window.addEventListener('scroll', listener)
  return () => {
    window.removeEventListener('scroll', listener)
  }
}, [])

// Example usage with TailwindCSS:
<div className={`bg-header/75 transition duration-500 ease-in-out ${animateHeader && 'bg-header/[0.95]'}`}>...</div>

function App() {
  const [checked, setChecked] = useState(false);
  const toggleChecked = () => setChecked(value => !value);
  return (
    <input
      type="checkbox"
      checked={checked}
      onChange={toggleChecked}
    />
  );
}

// making all uppercase
city.toUpperCase();

//removing spaces and making all lowercase
city = city.trim().toLowerCase();

//capitalizing the first letter
cityCapitalized = city.charAt(0).toUpperCase() + city.slice(1);

onClick={() => window.open(url, "_blank")}

import { useEffect } from 'react';

export const useClickOutside = (ref, setIsModalOpen) => {
  useEffect(() => {
    function handleClickOutside(event) {
      if (ref.current && !ref.current.contains(event.target)) {
        setIsModalOpen(false)
      }
    }
    document.addEventListener("mousedown", handleClickOutside);
    return () => {
      document.removeEventListener("mousedown", handleClickOutside);
    };
  }, [ref]);
};

<section style={{backgroundColor: color}}></section>

class Hello extends Component {
  constructor (props) {
    super(props)
    this.state = { visible: true }
  }
}

 

class Hello extends Component {
    state = { visible: true }
  }
}

React.createClass({ ... })
React.isValidElement(c)

ReactDOM.render(<Component />, domnode, [callback])
ReactDOM.unmountComponentAtNode(domnode)

MyCo.propTypes = {
  list: PropTypes.array,
  ages: PropTypes.arrayOf(PropTypes.number),
  user: PropTypes.object,
  user: PropTypes.objectOf(PropTypes.number),
  message: PropTypes.instanceOf(Message)
}

import React, { useState, useEffect } from 'react';

function Example() {
  const [count, setCount] = useState(0);

  // Similar to componentDidMount and componentDidUpdate:
  useEffect(() => {
    // Update the document title using the browser API
    document.title = `You clicked ${count} times`;
  }, [count]);

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

 

 

 

 

 

function ExampleWithManyStates() {
  // Declare multiple state variables!
  const [age, setAge] = useState(42);
  const [fruit, setFruit] = useState('banana');
  const [todos, setTodos] = useState([{ text: 'Learn Hooks' }]);
  // ...
}