js通过class获取标签里面的内容——看源码：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
<p class="demo">演示</p>
</body>
<style>
</style>
<script>
window.onload = function () {
var demo = document.getElementsByClassName("demo");
console.log(demo[0].innerText);
}
</script>
</html>
修改class属性——看源码
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
<p class="demo">演示</p>
</body>
<style>
.attribute-changes{
color:blue;
}
</style>
<script>
window.onload = function () {
var demo = document.getElementsByClassName("demo");
demo[0].className="attribute-changes";//属性修改
}
</script>
</html>效果：
