增删表格·

html

1.引入bootstrap
<link rel="stylesheet" href="http://libs.baidu.com/bootstrap/3.0.3/css/bootstrap.min.css">
<script src="http://libs.baidu.com/bootstrap/3.0.3/js/bootstrap.min.js"></script>
<table class="table table-bordered text-center">
    <tr>
        <td>书名</td>
        <td>作者</td>
        <td>价格</td>
    </tr>
    <tr>
        <td>红玫瑰与白玫瑰</td>
        <td>张爱玲</td>
        <td>￥23.5</td>
    </tr>
    <tr>
        <td>你若安好，便是晴天</td>
        <td>安意如</td>
        <td>￥33.5</td>
    </tr>
    <tr>
        <td>人生若只如初见</td>
        <td>纳兰容若</td>
        <td>￥24.5</td>
    </tr>
</table>
<button>增加一行</button>
<button>删除一行</button>
<button>复制一行</button>
<button>改变标题样式</button>
<button>
    <input type="text" placeholder="删除第几行" id="input">
    <span style="border: 1px solid red" >删除</span>
</button>

js

 var tr = document.getElementsByTagName("tr");
    var btn = document.getElementsByTagName("button");
    var tb = document.getElementsByTagName("tbody")[0];
    var span = document.getElementsByTagName("span")[0];
     btn[0].onclick = function(){
        var tr1 = document.createElement("tr");
        tr1.innerHTML = "<td>人生若只如初见</td><td>纳兰容若</td><td>￥24.5</td>";
        // tb.appendChild(tr1);  /*在tb的后面添加*/
         tb.insertBefore(tr1,tr[1]);/*在已存在的tr[1]前面插入tr1*/
        console.log(tr1.innerHTML);
    };
     btn[1].onclick = function(){
             tb.removeChild(tr[tr.length -1]);//删除最后一行 tr的长度减一
     };
     btn[2].onclick =function () {
          var tr2 = tr[tr.length-2].cloneNode(true);
          tb.appendChild(tr2);
     };
     btn[3].onclick =function () {
         tr[0].style.backgroundColor = "red"
     };
      span.onclick = function () {
          var inp =document.getElementById("input").value;
          var inp1 = parseInt(inp); /*对inp取整作为tr的值*/
          tb.removeChild(tr[inp1]);
      }