1、DOM节点的增删改
增加标签：appendChild
删除标签：removeChild
修改标签：replaceChild
2、添加CSS样式：
p_ele.style.color="red";
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<style>
.v1,.v2,.v3{
300px;
height: auto;
}
.v1{
background-color: #2459a2;
}
.v2{
background-color: red;
}
.v3{
background-color: deepskyblue;
}
</style>
</head>
<body>
<div class="v1">
<button class="but1">增</button>
div1
</div>
<div class="v2">
<button class="but2">删</button>
div2</div>
<div class="v3">
<button class="but3">改</button>
div3
<p>hello v3</p>
</div>
</body>
<script>
var add_ele=document.getElementsByClassName("but1")[0];
var v1_ele=document.getElementsByClassName("v1")[0];
//<!-- 插入新的标签appendChild与内容-->
add_ele.onclick=function () {
//创建P标签
var p_ele=document.createElement("p");
//写入内容
p_ele.innerHTML="hello p";
// 添加css样式
p_ele.style.color="red";
//在<div class="v1">下插入P标签
v1_ele.appendChild(p_ele);
};
// 删除标签 removeChild
var del_ele=document.getElementsByClassName("but2")[0];
var sons=v1_ele.getElementsByTagName("p");
del_ele.onclick=function () {
if(sons.length!=0){
v1_ele.removeChild(sons[0])
}
}
// 修改标签 replaceChild
var up_ele=document.getElementsByClassName("but3")[0];
var v3_ele=document.getElementsByClassName("v3")[0];
up_ele.onclick=function () {
var p_ele=v3_ele.getElementsByTagName("p")[0];
var img_ele=document.createElement("img");
img_ele.src="2.jpg";
//标签替换
if(p_ele!=undefined){
v3_ele.replaceChild(img_ele,p_ele)
}
}
</script>
</html>