JQ DOM元素 创建 添加 删除

创建元素

    // 创建元素节点
    $('<p></p>');
    // 创建属性节点
    $('<p class="wow"></p>');
    // 创建文本节点
    $('hello world');
    // 结合更实用
    $('<p class="wow">hello world</p>');

添加元素

append() 在元素内部的结尾插入内容

    $('p').append('<span>内部结尾</span>')

appendTo() 插入到所选元素内部的结尾

结果和 append() 一样 只是颠倒了位置

    <p class="one">Always believe that good things are going to happen</p>
    <p class="two">Always believe that good things are going to happen</p>
    <p class="three">Always believe that good things are going to happen</p>
    <span>new</span>
    <script>
        $('span').appendTo('.two')
    </script>

prepend() 在元素内部的开头插入内容

    $('p').prepend('<span>内部开头</span>')

prependTo() 插入到所选元素内部的头部

结果和 prepend() 一样 只是颠倒了位置

    <p class="one">Always believe that good things are going to happen</p>
    <p class="two">Always believe that good things are going to happen</p>
    <p class="three">Always believe that good things are going to happen</p>
    <span>new</span>
    <script>
        $('span').prependTo('.two')
    </script>

### after() 在元素外部之后插入内容
```

$('p').after('<span>外部后面</span>')

![](https://images2018.cnblogs.com/blog/1321525/201809/1321525-20180907185454985-1055904183.png)
<br />
### before() 在元素外部之前插入内容

$('p').before('<span>外部前面</span>')

![](https://images2018.cnblogs.com/blog/1321525/201809/1321525-20180907185623794-1105993898.png)
<br />
## 删除元素
### remove()  删除整个元素

<p>Always believe that good things are going to happen</p>
<span>Persist</span>
<p>Always believe that good things are going to happen</p>
<span class="txt">Persist</span>
<script>
    $('span').remove();
    $('span').remove('.txt');  // 可筛选
</script>

![](https://images2018.cnblogs.com/blog/1321525/201809/1321525-20180908092327587-2000278392.png)
![](https://images2018.cnblogs.com/blog/1321525/201809/1321525-20180908092259179-1874399156.png)
<br />
### empty() 清空元素的所有子节点

<p>Always believe that good things are going to happen</p>
<span>Persist</span>
<p>Always believe that good things are going to happen</p>
<span class="txt"><a href="">Persist</a></span>
<script>
    $('span').empty();
</script>

![](https://images2018.cnblogs.com/blog/1321525/201809/1321525-20180908092541891-730462301.png)
<br />