Tạo vertical tab menu với CSS và JavaScript

Để tạo vertical tab menu với CSS và JavaScript, code như sau:

Ví dụ

<!DOCTYPE html>
<html>
<head>
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <style>
    * {
      box-sizing: border-box
    }
    .tab {
      float: left;
      border: 1px solid blue;
      background-color: black;
      width: 20%;
      height: 200px;
    }
    .tab button {
      display: block;
      background-color: inherit;
      color: white;
      padding: 22px 16px;
      width: 100%;
      border: none;
      outline: none;
      text-align: left;
      cursor: pointer;
      transition: 0.3s;
      font-size: 17px;
    }
    .tab button:hover {
      background-color: gray;
    }
    .tab button.active {
      background-color: #006400;
    }
    .demo2 {
      float: left;
      padding: 0px 10px;
      border: 1px solid;
      width: 70%;
      border-left: none;
      height: 200px;
    }
  </style>
</head>
<body>
  <h2>Examination</h2>
  <p>Following is the exam information:</p>
  <div class="tab">
    <button class="demo" onclick="infofunc(event, 'dates')" id="current">Exam Dates</button>
    <button class="demo" onclick="infofunc(event, 'centre')">Exam Centre</button>
  </div>
  <div id="dates" class="demo2">
    <h3>Dates</h3>
    <p>Exam date will be announced on 25th March.</p>
  </div>
  <div id="centre" class="demo2">
    <h3>Centre</h3>
    <p>Exam Centre will be announced on 30th March.</p>
  </div>
  <script>
    function infofunc(e, info) {
      var i, content, links;
      content = document.getElementsByClassName("demo2");
      for (i = 0; i < content.length; i++) {
        content[i].style.display = "none";
      }
      links = document.getElementsByClassName("demo");
      for (i = 0; i < links.length; i++) {
        links[i].className = links[i].className.replace(" active", "");
      }
      document.getElementById(info).style.display = "block";
      e.currentTarget.className += " active";
    }
    document.getElementById("current").click();
  </script>
</body>
</html>

Kết quả

Code này cho kết quả:

Click vào tab, ví dụ "Exam Centre":