jQuery addClass example

Change class name on click in jQuery

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

var cartItems = {};
var items = []
cartItems.items = items;

var name = "Jeans";
var price = 2.19;
var quantity = 1;
var item = { "name": name, "price": price, "quantity": quantity}

items.forEach(function(item) {
				  if (item.name === name) {
					item.quantity = 2
					return;	
				  }
					
          });
 cartItems.items.push(item);
alert(JSON.stringify(cartItems));