jQuery addClass example

Change class name on click in jQuery

by Pradeep K. Pant

HTML

<link rel="stylesheet" href="https://use.fontawesome.com/releases/v5.7.2/css/all.css">
<script src="https://code.jquery.com/jquery-3.3.1.min.js"></script>
<script src="https://code.jquery.com/ui/1.12.1/jquery-ui.min.js"></script>
<!DOCTYPE html>
<html>
<head>
<title>Accordion jQuery demo</title>
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="https://use.fontawesome.com/releases/v5.7.2/css/all.css">
<link rel="stylesheet" type="text/css" href="css/show-hide-accordion.css" />
<script
  src="https://code.jquery.com/jquery-3.3.1.min.js"
  integrity="sha256-FgpCb/KJQlLNfOu91ta32o/NMZxltwRo8QtmkMRdAu8="
  crossorigin="anonymous"></script>
  <script
  src="https://code.jquery.com/ui/1.12.1/jquery-ui.min.js"
  integrity="sha256-VazP97ZCwtekAsvgPBSUwPFKdrwD3unUfSGVYrahUqU="
  crossorigin="anonymous"></script> 
</head>
<body>
<button class="menu_accordion">Top</button>
<div class="menu_panel">
<a href="#" class="menu_panel_button">&nbsp;&nbsp;&nbsp;&nbsp;<i class="fas fa-user fa-fw" aria-hidden="true"></i>Child1</a>
<a href="#" class="menu_panel_button">&nbsp;&nbsp;&nbsp;&nbsp;<i class="fas fa-user fa-fw" aria-hidden="true"></i>Child2</a> 
<a href="#" class="menu_panel_button">&nbsp;&nbsp;&nbsp;&nbsp;<i class="fas fa-user fa-fw" aria-hidden="true"></i>Child3</a>
</div>
<script src="js/show-hide-accodion.js"></script>
</body>
</html>

CSS

.menu_accordion {
  background-color: #2A3F54;
  color: #fff;
  cursor: pointer;
  padding: 10px 10px 10px 15px;
  width: 100%;
  border: none;
  text-align: left;
  outline: none;
  font-size: 13px;
  transition: 0.4s;
}
.menu_accordion:hover {
	background-color: rgb(115,135,156);
	color: #fff;
}
.menu_accordion:after {
  content: '\002B';
  color: #fff;
  font-weight: bold;
  float: right;
  margin-left: 5px;
}
.menu_accordion i,
.menu_panel_button {
	margin-right: 5px;
}
.menu_panel {
  padding: 0;
  background-color: #fff;
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.2s ease-out;
}
.menu_panel_button {
    width: 100%;
    color: white;
    text-decoration: none;
    text-align: left;
    font-size: 13px;
    transition: 0.4s;
    cursor: pointer;
    display: inline-block;
    padding: 7px 0 7px 30px;
    border-left: 5px solid white;
    background: rgb(115,135,156);
}
.menu_panel_button:hover {
	border-left: 5px solid rgb(115,135,156);
}

JavaScript

var acc = document.getElementsByClassName("menu_accordion");
var i;
for (i = 0; i < acc.length; i++) {
  acc[i].addEventListener("click", function() {
    this.classList.toggle("active");
    var panel = this.nextElementSibling;
    if (panel.style.maxHeight){
      panel.style.maxHeight = null;
    } else {
      panel.style.maxHeight = panel.scrollHeight + "px";
    } 
  });
}