W3Schools Tryit Editor

<!DOCTYPE html>
<html>
<style>
.filterDiv {
  float: left;
  background-color: #2196F3;
  color: #ffffff;
  width: 100px;
  line-height: 100px;
  text-align: center;
  margin: 2px;
  display: none;
}

.show {
  display: block;
}

.container {
  margin-top: 20px;
  overflow: hidden;
}

/* Style the buttons */
.btn {
  border: none;
  outline: none;
  padding: 12px 16px;
  background-color: #f1f1f1;
  cursor: pointer;
}

.btn:hover {
  background-color: #ddd;
}

.btn.active {
  background-color: #666;
  color: white;
}
</style>
<body>

<h2>Filter DIV Elements</h2>

<div id="myBtnContainer">
  <button class="btn active" onclick="filterSelection('all')"> Show all</button>
  <button class="btn" onclick="filterSelection('cars')"> Cars</button>
  <button class="btn" onclick="filterSelection('animals')"> Animals</button>
  <button class="btn" onclick="filterSelection('fruits')"> Fruits</button>
  <button class="btn" onclick="filterSelection('colors')"> Colors</button>
</div>

<div class="container">
  <div class="filterDiv cars">BMW</div>
  <div class="filterDiv colors fruits">Orange</div>
  <div class="filterDiv cars">Volvo</div>
  <div class="filterDiv colors">Red</div>
  <div class="filterDiv cars">Ford</div>
  <div class="filterDiv colors">Blue</div>
  <div class="filterDiv animals">Cat</div>
  <div class="filterDiv animals">Dog</div>
  <div class="filterDiv fruits">Melon</div>
  <div class="filterDiv fruits animals">Kiwi</div>
  <div class="filterDiv fruits">Banana</div>
  <div class="filterDiv fruits">Lemon</div>
  <div class="filterDiv animals">Cow</div>
</div>

// Add active class to the current button (highlight it)
var btnContainer = document.getElementById("myBtnContainer");
var btns = btnContainer.getElementsByClassName("btn");
for (var i = 0; i < btns.length; i++) {
  btns[i].addEventListener("click", function(){
    var current = document.getElementsByClassName("active");
    current[0].className = current[0].className.replace(" active", "");
    this.className += " active";
  });
}
</script>

</body>
</html>

​x
 
<!DOCTYPE html><html><style>.filterDiv {  float: left;  background-color: #2196F3;  color: #ffffff;  width: 100px;  line-height: 100px;  text-align: center;  margin: 2px;  display: none;}​.show {  display: block;}​.container {  margin-top: 20px;  overflow: hidden;}​/* Style the buttons */.btn {  border: none;  outline: none;  padding: 12px 16px;  background-color: #f1f1f1;  cursor: pointer;}​.btn:hover {  background-color: #ddd;}​.btn.active {  background-color: #666;  color: white;}</style><body>​<h2>Filter DIV Elements</h2>​<div id="myBtnContainer">  <button class="btn active" onclick="filterSelection('all')"> Show all</button>