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)
<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
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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>
![[Web front-end] Node.js quick start](https://img.php.cn/upload/course/000/000/067/662b5d34ba7c0227.png)
