Textarea running box effect code implemented by javascript without specifying id in batches_javascript skills

I just learned some operating methods and attributes of the DOM node tree, and I tried to write an example without manually setting the id and double-click event. After struggling for a long time, I finally figured it out. The code is as follows: (Explanation: Double-click to run the text. The code in the box, right-click to copy the code in it, save it as a *.htm file to test)

<title>textarea running box effect</title> <style>textarea {width:100%;height:200px;font-family:"fixedsys";overflow-y:hidden;} </style> <textarea> <!--代码实例--> <!--代码实例--> <textarea> <!--代码实例--> <div id="testdiv"> </div> <!--代码实例--> <textarea> <!--代码实例--> <div id="testdiv"> </div> <!--代码实例-->

<script> /************************************************************************************************************************************ *copyright (C) ymk18@163.com QQ:334150781 URL http://hi.baidu.com/ymk18 欢迎交流 共同学习 共同探讨 共同进步 2009-05-04 PM 19:17 *************************************************************************************************************************************/ window.onload = function() { //把此函数绑定到onload事件上 var textarea = document.getElementsByTagName("textarea"); //把所有textarea元素存入数组变量textarea for (var i=0;i<textarea.length;i++) { //遍历该数组变量textarea textarea[i].setAttribute("id",i); //设置每个textarea元素的id属性 textarea[i].style.posHeight = textarea[i].scrollHeight; //重置高度值使textarea元素高度自适应，重要样式height:200px; textarea[i].ondblclick = function() { //自定义鼠标双击事件 runCode(this.id); //调用运行代码函数 } textarea[i].oncontextmenu = function() { //自定义鼠标右击事件 this.select(); //右击对象中的文本选中效果 copyCode(this.id); //调用复制代码函数 return false; //拦截浏览器默认行为 } } } //运行代码 function runCode(getId) { var code=document.getElementById(getId).firstChild.nodeValue; if (code!=""){ var newwin=window.open('','',''); newwin.opener = null newwin.document.write(code); newwin.document.close(); } } //复制代码 function copyCode(getId) { var text=document.getElementById(getId).firstChild.nodeValue; window.clipboardData.setData("Text",text); alert("内容已经复制到剪切板！"); } //保存代码 function saveCode(getId) { var code=document.getElementById(getId).firstChild.nodeValue; var winname = window.open('', '_blank', 'top=10000'); winname.document.open('text/html', 'replace'); winname.document.writeln(code); winname.document.execCommand('saveas','','code.htm'); winname.close(); } </script>[Ctrl A select all Note: <script> var para = document.createElement("p"); //创建一个p元素节点并赋值给para变量 alert(para.nodeName); //显示元素节点的名字 alert(para.nodeType); //nodeType的值若为1->元素节点；2->属性节点；3->文本节点 </script>If you need to introduce external Js, you need to refresh to execute <script> window.onload = function() { var para = document.createElement("p"); var txt1 = document.createTextNode("I inserted "); para.appendChild(txt1); var emphasis = document.createElement("em"); var txt2 = document.createTextNode("this"); emphasis.appendChild(txt2); para.appendChild(emphasis); var txt3 = document.createTextNode(" content."); para.appendChild(txt3); var testdiv = document.getElementById("testdiv"); testdiv.appendChild(para); } </script>]<script> window.onload = function() { var para = document.createElement("p"); var txt1 = document.createTextNode("I inserted "); var emphasis = document.createElement("em"); var txt2 = document.createTextNode("this"); var txt3 = document.createTextNode(" content."); para.appendChild(txt1); emphasis.appendChild(txt2); para.appendChild(emphasis); para.appendChild(txt3); var testdiv = document.getElementById("testdiv"); testdiv.appendChild(para); } </script>