.length
分类：属性 > jQuery对象实例的属性
返回: Integer
length
示例
计数div，点击它们以添加更多div。
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>length demo</title>
<style>
body {
cursor: pointer;
}
div {
width: 50px;
height: 30px;
margin: 5px;
float: left;
background: green;
}
span {
color: red;
}
</style>
<script src="https://code.jquery.com/jquery-1.10.2.js"></script>
</head>
<body>
<span></span>
<div></div>
<script>
$( document.body )
.click(function() {
$( document.body ).append( $( "<div>" ) );
var n = $( "div" ).length;
$( "span" ).text( "There are " + n + " divs." +
"Click to add more.");
})
// Trigger the click to start
.trigger( "click" );
</script>
</body>
</html>
演示结果