1
//獲取偽元素
// CSS代碼
2 #myId:before {
3 content: "hello world!";
4 display: block;
5 width: 100px;
6 height: 100px;
7 background: red;
8 }
9 // HTML代碼
10 <div id="myId"></div>
11 // JS代碼
12 var myIdElement = document.getElementById("myId");
13 var beforeStyle = window.getComputedStyle(myIdElement, ":before");
14 console.log(beforeStyle); // [CSSStyleDeclaration Object]
15 console.log(beforeStyle.width); // 100px
16 console.log(beforeStyle.getPropertyValue("width")); // 100px
17 console.log(beforeStyle.content); // "hello world!
//更改樣式:
1 // CSS代碼
2 .red::before {
3 content: "red";
4 color: red;
5 }
6 .green::before {
7 content: "green";
8 color: green;
9 }
10 // HTML代碼
11 <div class="red">內容內容內容內容</div>
12 // jQuery代碼
13 $(".red").removeClass('red').addClass('green');
