jQuery addClass example

Change class name on click in jQuery

by Hilarius Doren

HTML

<div id="banner-message">
  <p>Hello World</p>
  <button>Change color</button>
</div>

CSS

body {
  background: #20262E;
  padding: 20px;
  font-family: Helvetica;
}

#banner-message {
  background: #fff;
  border-radius: 4px;
  padding: 20px;
  font-size: 25px;
  text-align: center;
  transition: all 0.2s;
  margin: 0 auto;
  width: 300px;
}

button {
  background: #0084ff;
  border: none;
  border-radius: 5px;
  padding: 8px 14px;
  font-size: 15px;
  color: #fff;
}

#banner-message.alt {
  background: #0084ff;
  color: #fff;
  margin-top: 40px;
  width: 200px;
}

#banner-message.alt button {
  background: #fff;
  color: #000;
}

JavaScript

// find elements
var banner = $("#banner-message")
var button = $("button")

// handle click and add class
button.on("click", function(){
  banner.addClass("alt")
})


const nthPrime = (number) => {
  let primes = [2];
  let higherDivisorLimit;
  let isPrime;
  for(let i = 3; primes.length < number; i+=2) {
    higherDivisorLimit = Math.sqrt(i) + 1;
    isPrime = true;
    for(let j = 0; primes[j] < higherDivisorLimit; j++) {
      if(i % primes[j] === 0) {
        isPrime = false;
        break;
      }
    }
    if(isPrime) primes.push(i);
  }
  return primes[primes.length - 1];
}
alert(nthPrime(10001));