SOURCE

console 命令行工具 X clear 

                    

                        
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console

            
window.onload=function(){
    var oTds=document.getElementsByTagName("td");
    for(var i=0;i<oTds.length;++i){
        oTds[i].onclick=function(){
            //获取父元素
            var oParent=this.parentNode;
            //为父元素添加样式
            oParent.style.color="white";
            oParent.style.backgroundColor="lightskyblue";
        }
    }

    var oUI=document.getElementById("list");
    var oChildNode=oUI.childNodes;
    var oChildElement=oUI.children;

    console.log("There are "+oChildNode.length+" child nodes in list");
    console.log("There are "+oChildElement.length+" child nodes in list");

    var oBtn=document.getElementById("btn");
    
    oBtn.onclick=function(){
        //删除最后的字节点
        //oUI.removeChild(oUI.lastChild);

        //删除最后的元素节点
        // if(oUI.lastChild.nodeType==3){
        //     oUI.removeChild(oUI.lastChild);
        //     oUI.removeChild(oUI.lastChild);
        // }
        // else{
        //     oUI.removeChild(oUI.lastChild);
        // }

        //oUI.removeChild(oUI.lastElementChild);
        
        //删除兄弟元素节点
        // var preLastElement=oUI.lastElementChild.previousElementSibling;
        // oUI.removeChild(preLastElement);

        //删除兄弟节点
        var preLastNode=oUI.lastElementChild.previousSibling;
        oUI.removeChild(preLastNode);
    }
}

            
<!DOCTYPE html> 
<html>
<head>
    <meta charset="utf-8" />
    <title></title>
    <style type="text/css">
        
    </style>
    <script>
       
    </script>
</head>
<body>
    <table>
        <caption>考试成绩表</caption>
        <tr>
            <td>小明</td>
            <td>80</td>
            <td>80</td>
            <td>80</td>
        </tr>
        <tr>
            <td>小红</td>
            <td>90</td>
            <td>90</td>
            <td>90</td>
        </tr>
        <tr>
            <td>小杰</td>
            <td>100</td>
            <td>100</td>
            <td>100</td>
        </tr>
    </table>

    <ul id="list">
        <li>HTML</li>
        <li>CSS</li>
        <li>JavaScript</li>
        <li>jQuery</li>
        <li>Vue.js</li>
    </ul>
    <button id="btn">删除</button>
</body>
</html>