Learus/react-material-ui-carousel: A Generic carousel UI component for React using Material UI.

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>

javascript:(d=>{var css=`:root{background-color:#f1f1f1;filter:invert(1) hue-rotate(180deg)}img:not([src*=".svg"]),picture,video{filter: invert(1) hue-rotate(180deg)}`,style,id="dark-mode",ee=d.getElementById(id);if(null!=ee)ee.parentNode.removeChild(ee);else {style = d.createElement('style');style.type="text/css";style.id=id;if(style.styleSheet)style.styleSheet.cssText=css;else style.appendChild(d.createTextNode(css));(d.head||d.querySelector('head')).appendChild(style)}})(document)

/**
* Rewrites text
* @param {String} text The text to rewrite.
* @returns {Promise.<String[]>} Resolves into a list of about 10 rewritten versions. (Or rejects with an error)
* @example 
* var rewritten  = await rewrite("Sometimes I just want to code in JavaScript all day.");
* // ⇒ [
* //    "I sometimes just want to code JavaScript all day.",
* //    "JavaScript is my favorite programming language sometimes.",
* //    "I sometimes wish I could code in JavaScript all day.",
* //    "JavaScript is sometimes all I want to do all day.",
* //    "I like JavaScript sometimes and want to code all day long.",
* //    "Some days I just want to work all day in JavaScript.",
* //    "It's not uncommon for me to just want to code in JavaScript all day.",
* //    "My favorite thing to do sometimes is just code JavaScript all day.",
* //    "My favourite coding language is JavaScript, which I can code all day.",
*//     "JavaScript is my preferred language sometimes, since it lets me code all day.",
*// ];
*/
function rewrite(text) {
  return new Promise(async (resolve, reject) => {
    var { suggestions, error_code, error_msg, error_msg_extra } = await fetch(
      "https://api.wordtune.com/rewrite-limited",
      {
        headers: {
          accept: "*/*",
          "accept-language": "en-US,en;q=0.9",
          "content-type": "application/json",
          "x-wordtune-origin": "https://www.wordtune.com",
        },
        referrer: "https://www.wordtune.com/",
        body: JSON.stringify({
          action: "REWRITE",
          text: text,
          start: 0,
          end: text.length,
          selection: {
            wholeText: text,
            start: 0,
            end: text.length,
          },
        }),
        method: "POST",
      }
    ).then((res) => res.json());
    if (error_code || error_msg || error_msg_extra) {
      reject({
        code: error_code,
        message: error_msg,
        message_extra: error_msg_extra,
      });
    } else {
      resolve(suggestions);
    }
  });
}

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]);
};

$('.button').click(function(){

  var buttonId = $(this).attr('id');

  $('#modal-container').removeAttr('class').addClass(buttonId);

  $('body').addClass('modal-active');

})

​

$('#modal-container').click(function(){

  $(this).addClass('out');

  $('body').removeClass('modal-active');

});

$('.button').click(function(){

  var buttonId = $(this).attr('id');

  $('#modal-container').removeAttr('class').addClass(buttonId);

  $('body').addClass('modal-active');

})

​

$('#modal-container').click(function(){

  $(this).addClass('out');

  $('body').removeClass('modal-active');

});

var element = document.querySelectorAll('.elementClass');
if (typeof(element) != 'undefined' && element != null) {
    //your code here
}

<!-- JavaScript Bundle with Popper -->
<script src="https://cdn.jsdelivr.net/npm/bootstrap@5.0.0/dist/js/bootstrap.bundle.min.js" integrity="sha384-p34f1UUtsS3wqzfto5wAAmdvj+osOnFyQFpp4Ua3gs/ZVWx6oOypYoCJhGGScy+8" crossorigin="anonymous"></script>