一、基础选择器
All Selector ("*")
选择所有元素,此选择器使用要慎重，其速度是极其慢的
<!DOCTYPE html>
<html>
<head>
<style>
h3 { margin: 0; }
div,span,p {
width: 80px;
height: 40px;
float:left;
padding: 10px;
margin: 10px;
background-color: #EEEEEE;
}
#test {
width: auto; height: auto; background-color: transparent;
}
</style>
<script src="./jquery-3.6.0.min.js"></script>
</head>
<body>
<div id="test">
<div>DIV</div>
<span>SPAN</span>
<p>P <button>Button</button></p>
</div>
<script>
var elementCount = $("#test").find("*").css("border","3px solid red").length;
$("body").prepend("<h3>" + elementCount + " elements found</h3>");</script>
</body>
</html>
复制代码Class Selector (".class")
选择给定样式类名的所有元素。
<!DOCTYPE html>
<html>
<head>
<style>
div,span {
width: 100px;
height: 40px;
float:left;
padding: 10px;
margin: 10px;
background-color: #EEEEEE;
}
</style>
<script src="./jquery-3.6.0.min.js"></script>
</head>
<body>
<div class="notMe">div class="notMe"</div>
<div class="myClass">div class="myClass"</div>
<span class="myClass">span class="myClass"</span>
<script>$(".myClass").css("border","3px solid red");</script>
</body>
</html>
复制代码Element Selector ("element")
根据给定（html）标记名称选择所有的元素。
<!DOCTYPE html>
<html>
<head>
<style>
div,span {
width: 60px;
height: 60px;
float:left;
padding: 10px;
margin: 10px;
background-color: #EEEEEE;
}
</style>
<script src="./jquery-3.6.0.min.js"></script>
</head>
<body>
<div>DIV1</div>
<div>DIV2</div>
<span>SPAN</span>
<script>$("div").css("border","9px solid red");</script>
</body>
</html>
复制代码ID Selector ("#id")
选择一个具有给定id属性的单个元素。
<!DOCTYPE html>
<html>
<head>
<style>
div {
width: 90px;
height: 90px;
float:left;
padding: 5px;
margin: 5px;
background-color: #EEEEEE;
}
</style>
<script src="./jquery-3.6.0.min.js"></script>
</head>
<body>
<div id="notMe"><p>id="notMe"</p></div>
<div id="myDiv">id="myDiv"</div>
<script>$("#myDiv").css("border","3px solid red");</script>
</body>
</html>
复制代码Child Selector ("parent > child")
选择所有指定“parent”元素中指定的"child"的直接子元素。
<!DOCTYPE html>
<html>
<head>
<style>
body { font-size:14px; }
</style>
<script src="./jquery-3.6.0.min.js"></script>
</head>
<body>
<ul class="topnav">
<li>Item 1</li>
<li>Item 2
<ul><li>Nested item 1</li><li>Nested item 2</li><li>Nested item 3</li></ul>
</li>
<li>Item 3</li>
</ul>
<script>$("ul.topnav > li").css("border", "3px double red");</script>
</body>
</html>
复制代码