​x
 
<!DOCTYPE html>
<html>
<head>
<style> 
#myDIV {
  width: 500px;
  height: 500px;
  background-color: lightblue;
}
</style>
</head>
<body>
​
<p>点击“试一试”按钮可在隐藏和显示 DIV 元素之间切换：</p>
​
<button onclick="myFunction()">试一试</button>
​
<div id="myDIV">
This is my DIV element.
</div>
​
<p><b>注释：</b>当 display 属性设置为 “none” 时，元素不会占用任何空间。</p>
​
<script>
function myFunction() {
  var x = document.getElementById('myDIV');
  if (x.style.display === 'none') {
    x.style.display = 'block';
  } else {
    x.style.display = 'none';
  }
}
</script>
​
</body>
</html>
​