选择器的分离

来源：1-19 自由编程

言无月

2020-08-06 03:01:38

$("div.div2").css("background-color","blue");中$("div.div2")是什么选择器怎么使用

<!DOCTYPE html >

<html>
<head>
<meta charset="UTF-8">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>jQuery练习</title>

<style type="text/css">
.div1{

float: left;
width: 50px;
line-height: 30px;
background-color: lightgray;
margin-left: 10px;
text-align: center;
vertical-align: middle;
}
.div2{
width: 300px;
height: 300px;
border: solid gray 1px;
margin-top: 60px;
color: red;
}
</style>

</head>
<body>
<h2>请选择背景颜色</h2>
<div>
<div id="blue" class="div1">蓝色</div>
<div id="green" class="div1">绿色</div>
</div>
<div class="div2" id="bg">
</div>
<div>输入颜色首字母： <input type="text" name="color"></div>
<script type="text/javascript" src="js/jquery-3.3.1.js"></script>
<script type="text/javascript">
window.onload = function(){
alert("欢迎来到三千世界");
}
$("#blue").on("click",function(){
alert("欢迎来到三千世界");
$("div.div2").css("background-color","blue");
$("div.div2").text("蓝色背景");
});
</script>
</body>
</html>