/* AJAX v1.4 HJF 2009-7-5 */ function AjaxDO(){ this.HttpRequest = null; this.openMethod = null; //HTTP请求的方法,为Get、Post 或者Head this.openURL = null; //是目标URL。基于安全考虑,这个URL 只能是同网域的,否则会提示“没有权限”的错误。 this.openAsync = null; //是指定在等待服务器返回信息的时间内是否继续执行下面的代码。如果为False,则不会继续执行,直到服务器返回信息。默认为True。 this.ProcessRequestFunction = function(_HttpRequest) {return;} //处理返回信息的函数入口 this.ProcessRequestParam = null; //处理访问信息时的附加参数 this.LoadingImg = null; //正在载入的图片,一般为.gif动画 //初始化HttpRequest this.InitHttpRequest = function(){ var http; // try { // http = new ActiveXObject("Msxml2.XMLHTTP"); // } catch(e) { // try { // http = new ActiveXObject("Microsoft.XMLHTTP"); // } catch(e) { // http = false; // } // } try { if(window.ActiveXObject){ for(var i=5; i; i--){ try{ if(i==2){ http = new ActiveXObject("Microsoft.XMLHTTP"); }else{ http = new ActiveXObject( "Msxml2.XMLHTTP." + i + ".0" ); } break; }catch(e){ //alert(i); http = false; } } }else if(window.XMLHttpRequest){ http = new XMLHttpRequest(); if(http.overrideMimeType){ http.overrideMimeType("text/xml"); } } }catch(e){ http = false; } if(!http){ Alert("不能创建XMLHttpRequest对象实例"); return http; } this.HttpRequest = http; return http; } //检测 this.HttpRequest this.checkHttpRequest = function(){ if(!this.HttpRequest){ return this.InitHttpRequest(); } return this.HttpRequest; } //修改MIME类别 //http.setRequestHeader("Content-Type", "application/x-www-form-urlencoded"); //如果要传文件或者Post 内容给服务器 //http.setRequestHeader("Content-Type","text/xml"); //http.setRequestHeader("Content-Type","gb2312"); this.setRequestHeader = function(mime){ if(!this.checkHttpRequest()){ return false; } try{ this.HttpRequest.setRequestHeader("Content-Type", mime); return true; }catch(e){ if(e instanceof Error){ Alert("修改MIME类别错误"); return false; } } } //设置状态改变的事件触发器 this.setOnReadyStateChange = function(funHandle, Param){ if(!this.checkHttpRequest()){ return false; } this.ProcessRequestFunction = funHandle; this.ProcessRequestParam = Param; return true; } this.setLoadingImg = function(ImgID){ this.LoadingImg = ImgID; } //建立HTTP连接 //open("method","URL"[,asyncFlag[,"userName"[, "password"]]]) this.Open = function(method, url, async, username, psw){ if(!this.checkHttpRequest()){ return false; } this.openMethod = method; this.openURL = url; this.openAsync = async; if((this.openMethod==null) || ((this.openMethod.toUpperCase()!="GET")&&(this.openMethod.toUpperCase()!="POST")&&(this.openMethod.toUpperCase()!="HEAD"))){ Alert("请指定HTTP请求的方法,为Get、Post 或者Head"); return false; } if((this.openURL==null)||(this.openURL=="")){ Alert("请指定目标URL"); return false; } try{ this.HttpRequest.open(this.openMethod, this.openURL, this.openAsync, username, psw); }catch(e){ if(e instanceof Error){ Alert("无法建立HTTP连接"); return false; } } if(this.openMethod.toUpperCase()=="POST"){ if(!this.setRequestHeader("application/x-www-form-urlencoded")){ Alert("修改MIME类别失败"); return false; } } if(this.openAsync){ //异步模式,程序继续执行 if(this.ProcessRequestFunction==null){ Alert("请指定处理返回信息的函数"); return false; } var _http_request_ajax = this.HttpRequest; var _this_ajax = this; this.HttpRequest.onreadystatechange = function(){ if(_http_request_ajax.readyState==4) { if(_http_request_ajax.status==200) { _this_ajax.ProcessRequestFunction(_http_request_ajax, _this_ajax.ProcessRequestParam, _this_ajax.LoadingImg); }else{ Alert("您所请求的页面有异常。"); return false; } } } } if(this.LoadingImg!=null){ funShow(this.LoadingImg); } return true; } //向服务器发出HTTP请求 //格式:name=value&anothername=othervalue&so=on this.Send = function(idata){ if(!this.checkHttpRequest()){ return false; } var data = null; if(this.openMethod.toUpperCase()=="POST"){ data = funEscapeAll(idata); } try{ this.HttpRequest.send(data); return true; }catch(e){ if(e instanceof Error){ Alert("向服务器发出HTTP请求失败"); return false; } } } //处理服务器返回的信息 this.getResponseText = function(type){ if(!this.checkHttpRequest()){ return false; } if(this.HttpRequest.readyState==4) { if(this.HttpRequest.status==200) { if((type!=null) && (type.toUpperCase()=="XML")){ return this.HttpRequest.responseXML; } return this.HttpRequest.responseText; }else{ Alert("您所请求的页面有异常。"); return false; } } } //停止当前请求 this.abort = function(){ if(!this.checkHttpRequest()){ return false; } if(this.LoadingImg!=null){ funHide(this.LoadingImg); } if(this.HttpRequest.readyState>0 && this.HttpRequest.readyState<4){ this.HttpRequest.abort(); } } } //===================================================================================== //公共函数 //===================================================================================== function $(_obj){ var o; if (typeof(_obj)!="string") return _obj; else{ try{ document.all; try{ o=document.all(_obj); }catch(e){ return null; } }catch(ee){ try{ o=document.getElementById(_obj); }catch(e){ return null; } } return o; } } function funEscapeAll(str){ var t = "&"; var s = str.split(t); if(s.length<=0) return str; for(var i=0; i<s.length; i++){ s[i] = funEscapeOne(s[i]); } return s.join(t); } function funEscapeOne(str){ var i = str.indexOf("="); if(i==-1) return str; var t = URLEncode(str.substr(i+1)); return str.substring(0, i+1)+t; } function URLEncode(str){ return encodeURIComponent(str); /* return escape(str).replace(/\+/g, "%2B"). replace(/\"/g,"%22"). replace(/\'/g, "%27"). replace(/\//g,"%2F"); */ } function funEscapeXML(content) { if (content == undefined) return ""; if (!content.length || !content.charAt) content = new String(content); var result = ""; var length = content.length; for (var i = 0; i < length; i++) { var ch = content.charAt(i); switch (ch) { case '&': result += "&"; break; case '<': result += "<"; break; case '>': result += ">"; break; case '"': result += """; break; case '\'': result += "'"; break; default: result += ch; } } return result; } function funShow(_obj){ if(typeof(_obj)=="object") _obj.style.visibility = "inherit"; else $(_obj).style.visibility = "inherit"; } function funHide(_obj){ if(typeof(_obj)=="object") _obj.style.visibility = "hidden"; else $(_obj).style.visibility = "hidden"; } function Alert(str){ alert(str); //window.status = str; } /* 使用例子: function processRequest(http_request, _val, _loading_img){ if(http_request.responseXML.documentElement){ //alert(decodeURIComponent(http_request.responseXML.documentElement.xml)); }else{ //alert(decodeURIComponent(http_request.responseText)); } alert(_val); funHide(_loading_img); } 1、GET var ajax = new AjaxDO(); ajax.setLoadingImg(_loading_img); ajax.setOnReadyStateChange(processRequest, _val); ajax.Open("GET", url, true); //异步模式,程序继续执行 ajax.Send(""); ajax.Open("GET", url, false); //非异步模式,程序等待 ajax.Send(""); var xml_doc = ajax.getResponseText("XML"); var text_doc = ajax.getResponseText("TEXT"); 2、POST var ajax = new AjaxDO(); ajax.setLoadingImg(_loading_img); ajax.setOnReadyStateChange(processRequest, _val); ajax.Open("POST", url, true); //异步模式,程序继续执行 ajax.Send(data); ajax.Open("POST", url, false); //非异步模式,程序等待 ajax.Send(data); var xml_doc = ajax.getResponseText("XML"); var text_doc = ajax.getResponseText("TEXT"); 注,客户端发送带有中文或HTML脚本的信息时,发送的信息必须调用:encodeURIComponent函数,例如: var data = encodeURIComponent($('message').value); 实际是调用了两次,Ajax类内部又调用一次。 服务端(Java版)需要做下转码: String message = request.getParameter("message"); message = URLDecoder.decode(message, "UTF-8"); */ 注,客户端发送带有中文或HTML脚本的信息时,发送的信息必须调用:encodeURIComponent函数,例如: String message = request.getParameter("message"); message = URLDecoder.decode(message, "UTF-8"); 2、Demo.html Ajax类<style type="text/css"><!-- #Layer1 { position:absolute; left:670px; top:11px; width:15px; height:15px; z-index:10000; background-color:#FF0000; font-size:13; border:none; visibility:hidden; } --></style><style type="text/css" bogus="1">#Layer1 { position:absolute; left:670px; top:11px; width:15px; height:15px; z-index:10000; background-color:#FF0000; font-size:13; border:none; visibility:hidden; }</style> </head> <body> <div id="Layer1"><img src="/static/imghwm/default1.png" data-src="http://www.jb51.net/article/indicator_flower.gif" class="lazy" / alt="JavaScript Ajax class example code" ></div> <script type="text/javascript" language="javascript"><!-- function processRequest(http_request, _val, _loading_img){ alert(http_request.responseXML.documentElement.xml); //alert(http_request.responseText); funHide(_loading_img); } // --></script> <script type="text/javascript" language="javascript"><!-- var url = "http://www.w3schools.com/xml/simple.xml"; var data = ""; var ajax = new AjaxDO(); function btnAjax1(){ //var ajax = new AjaxDO(); //ajax.InitHttpRequest(); ajax.abort(); ajax.setLoadingImg(document.getElementById("Layer1")); ajax.setOnReadyStateChange(processRequest); ajax.Open("GET", url, true); //异步模式,程序继续执行 ajax.Send(""); } function btnAjax2(){ //var ajax = new AjaxDO(); //ajax.InitHttpRequest(); ajax.abort(); ajax.Open("GET", url, false); //非异步模式,程序等待 ajax.Send(""); alert(ajax.getResponseText("XML").documentElement.xml); alert(ajax.getResponseText("TEXT")); } // --></script> <button >异步模式</button> <button >非异步模式</button> </body> </html>

JavaScript is widely used in websites, mobile applications, desktop applications and server-side programming. 1) In website development, JavaScript operates DOM together with HTML and CSS to achieve dynamic effects and supports frameworks such as jQuery and React. 2) Through ReactNative and Ionic, JavaScript is used to develop cross-platform mobile applications. 3) The Electron framework enables JavaScript to build desktop applications. 4) Node.js allows JavaScript to run on the server side and supports high concurrent requests.

Python is more suitable for data science and automation, while JavaScript is more suitable for front-end and full-stack development. 1. Python performs well in data science and machine learning, using libraries such as NumPy and Pandas for data processing and modeling. 2. Python is concise and efficient in automation and scripting. 3. JavaScript is indispensable in front-end development and is used to build dynamic web pages and single-page applications. 4. JavaScript plays a role in back-end development through Node.js and supports full-stack development.

C and C play a vital role in the JavaScript engine, mainly used to implement interpreters and JIT compilers. 1) C is used to parse JavaScript source code and generate an abstract syntax tree. 2) C is responsible for generating and executing bytecode. 3) C implements the JIT compiler, optimizes and compiles hot-spot code at runtime, and significantly improves the execution efficiency of JavaScript.

JavaScript's application in the real world includes front-end and back-end development. 1) Display front-end applications by building a TODO list application, involving DOM operations and event processing. 2) Build RESTfulAPI through Node.js and Express to demonstrate back-end applications.

The main uses of JavaScript in web development include client interaction, form verification and asynchronous communication. 1) Dynamic content update and user interaction through DOM operations; 2) Client verification is carried out before the user submits data to improve the user experience; 3) Refreshless communication with the server is achieved through AJAX technology.

Understanding how JavaScript engine works internally is important to developers because it helps write more efficient code and understand performance bottlenecks and optimization strategies. 1) The engine's workflow includes three stages: parsing, compiling and execution; 2) During the execution process, the engine will perform dynamic optimization, such as inline cache and hidden classes; 3) Best practices include avoiding global variables, optimizing loops, using const and lets, and avoiding excessive use of closures.

Python is more suitable for beginners, with a smooth learning curve and concise syntax; JavaScript is suitable for front-end development, with a steep learning curve and flexible syntax. 1. Python syntax is intuitive and suitable for data science and back-end development. 2. JavaScript is flexible and widely used in front-end and server-side programming.

Python and JavaScript have their own advantages and disadvantages in terms of community, libraries and resources. 1) The Python community is friendly and suitable for beginners, but the front-end development resources are not as rich as JavaScript. 2) Python is powerful in data science and machine learning libraries, while JavaScript is better in front-end development libraries and frameworks. 3) Both have rich learning resources, but Python is suitable for starting with official documents, while JavaScript is better with MDNWebDocs. The choice should be based on project needs and personal interests.


Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

SecLists
SecLists is the ultimate security tester's companion. It is a collection of various types of lists that are frequently used during security assessments, all in one place. SecLists helps make security testing more efficient and productive by conveniently providing all the lists a security tester might need. List types include usernames, passwords, URLs, fuzzing payloads, sensitive data patterns, web shells, and more. The tester can simply pull this repository onto a new test machine and he will have access to every type of list he needs.

WebStorm Mac version
Useful JavaScript development tools

Atom editor mac version download
The most popular open source editor

EditPlus Chinese cracked version
Small size, syntax highlighting, does not support code prompt function

DVWA
Damn Vulnerable Web App (DVWA) is a PHP/MySQL web application that is very vulnerable. Its main goals are to be an aid for security professionals to test their skills and tools in a legal environment, to help web developers better understand the process of securing web applications, and to help teachers/students teach/learn in a classroom environment Web application security. The goal of DVWA is to practice some of the most common web vulnerabilities through a simple and straightforward interface, with varying degrees of difficulty. Please note that this software