1. 删除元素
            
            
              html
              
              
            
          
             span{
       color: white;
       padding: 8px;
       margin: 5px;
       float: left;
    }
    .green {
       background-color: green;
    }
    .blue {
       background-color: blue;
    }
   <span class="green">green</span>
   <span class="blue">blue</span>
   <span class="green">333</span>
   <span class="blue">444</span>
        
- 使用 remove() -> 删除元素及其子元素,标签和内容一起删除
 指定元素.remove()
            
            
              javascript
              
              
            
          
          $(".green").remove()
        
- empty() -> 清空元素内容, 保留标签
 
            
            
              javascript
              
              
            
          
           $(".blue").empty()
        
2. 遍历元素
            
            
              html
              
              
            
          
          span{
  color: white;
  padding: 8px;
  margin: 5px;
  float: left;
 }
.green {
  background-color: green;
}
.blue {
  background-color: blue;
}
<h3>遍历元素</h3>
<span class="green">green</span>
<span class="green">blue</span>
<span class="green">333</span>
<span class="green">444</span>
        each():
$(selector).each(function(index,element))
// 参数function为遍历时的回调函数
// index为遍历元素的序列号,从0开始
// element是当前的元素,此时是dom元素
            
            
              javascript
              
              
            
          
           // 获取指定元素并遍历
 $(".green").each(function(index, element) {
      console.log(index)
      console.log(element)
 })
        