JQuery - 用.length屬性查看元素是否存在

時間 2019-11-08

標籤 jquery length 屬性查看元素是否存在欄目 JQuery 简体版

原文原文鏈接

<html>
<head>
 
<script type="text/javascript" src="jquery-1.10.2.js"></script>
 
</head>
 
<body>
 
<h1>jQuery check if an element exists</h1>
 
<script type="text/javascript">
 
  $(document).ready(function(){
 
    $("#buttonDiv1").click(function () {
 
	if($('#div1').length){
		alert("Div1 exists");
	}else{
		alert("Div1 does not exists");
	}
 
    });
 
    $("#buttonDiv2").click(function () {
 
	if($('#div2').length){
		alert("Div2 exists");
	}else{
		alert("Div2 does not exists");
	}
 
    });
 
  });
</script>
</head><body>
 
<div id="div1">
	<b>This is DIV element which has an ide of "div1"</b>
</div>
 
<br/>
<br/>
<br/>
 
<input type='button' value='div1 exists?' id='buttonDiv1'>
<input type='button' value='div2 exists?' id='buttonDiv2'>
 
</body>
</html>

相關標籤/搜索