Nota kajian JavaScript: Kesan jenis klien (enjin, penyemak imbas, platform, sistem pengendalian, peranti mudah alih)_kemahiran javascript

//取得用户代理字符串 并全部小写。
var ua = navigator.userAgent.toLowerCase();
document.write(ua);

var ua = navigator.userAgent.toLowerCase();
var isStrict = document.compatMode == "CSS1Compat"
isOpera = ua.indexOf("opera") > -1
isChrome = ua.indexOf("chrome") > -1
isSafari = !isChrome && (/webkit|khtml/).test(ua)
isSafari3 = isSafari && ua.indexOf('webkit/5') != -1
isIE = !isOpera && ua.indexOf("msie") > -1
isIE7 = !isOpera && ua.indexOf("msie 7") > -1
isIE8 = !isOpera && ua.indexOf("msie 8") > -1
isGecko = !isSafari && !isChrome && ua.indexOf("gecko") > -1
isGecko3 = isGecko && ua.indexOf("rv:1.9") > -1
isBorderBox = isIE && !isStrict 
isWin7 = ua.indexOf("nt 6.1") > -1
isVista = ua.indexOf("nt 6.0") > -1
isWin2003 = ua.indexOf("nt 5.2") > -1
isWinXp = ua.indexOf("nt 5.1") > -1
isWin2000 = ua.indexOf("nt 5.0") > -1
isWindows = (ua.indexOf("windows") != -1 || ua.indexOf("win32") != -1)
isMac = (ua.indexOf("macintosh") != -1 || ua.indexOf("mac os x") != -1)
isAir = (ua.indexOf("adobeair") != -1)
isLinux = (ua.indexOf("linux") != -1) 
var sys = "";
var broser = ""; 
if(isIE){
  broser = "IE 6";
}else if(isIE7){
  broser = "IE 7";
}else if(isIE8){
  broser = "IE 8";
}else if(isOpera){
  broser = "Opera";
}else if(isChrome){
  broser = "Chrome";
}else if(isSafari){
  broser = "Safari";
}else if(isSafari3){
  broser = "Safari3";
}else{
  broser = "Unknow";
} 
if(isWin7){
  sys = "Windows 7";
}else if(isVista){
  sys = "Vista";
}else if(isWinXp){
  sys = "Windows xp";
}else if(isWin2003){
  sys = "Windows 2003";
}else if(isWin2000){
  sys = "Windows 2000";
}else if(isWindows){
  sys = "Windows";
}else if(isMac){
  sys = "Macintosh";
}else if(isAir){
  sys = "Adobeair";
}else if(isLinux){
  sys = "Linux";
}else{
  sys = "Unknow";
}
document.write(ua);
alert(sys + ":" + broser);

var client = function(){
//呈现引擎
var engine = {
 ie   : 0,
 gecko : 0,
 webkit : 0,
 khtml : 0,
 opera : 0,
 //完整的版本号
 ver  : null
};
//浏览器
var browser = {
//主要浏览器
 ie   : 0,
 firefox : 0,
 konq  : 0,
 opera  : 0,
 chrome : 0,
 safari : 0,
 //具体的版本号
 ver   : null
};
//平台、设备和操作系统
var system ={
 win : false,
 mac : false,
 xll : false,
 //移动设备
 iphone  : false,
 ipod   : false,
 nokiaN  : false,
 winMobile : false,
 macMobile : false,
 //游戏设备
 wii : false,
 ps : false
};
//检测呈现引擎和浏览器
var ua = navigator.userAgent;
if (window.opera){
 engine.ver = browser.ver = window.opera.version();
 engine.opera = browser.opera = parseFloat(engine.ver);
} else if (/AppleWebKit\/(\S+)/.test(ua)){
 engine.ver = RegExp["$1"];
 engine.webkit = parseFloat(engine.ver);
 //确定是Chrome还是Safari
 if (/Chrome\/(\S+)/.test(ua)){
 browser.ver = RegExp["$1"];
 browser.chrome = parseFloat(browser.ver);
 } else if (/Version\/(\S+)/.test(ua)){
 browser.ver = RegExp["$1"];
 browser.safari = parseFloat(browser.ver);
 } else {
 //近似地确定版本号
 var safariVersion = 1;
 if(engine.webkit < 100){
  safariVersion = 1;
 } else if (engine.webkit < 312){
  safariVersion = 1.2;
 } else if (engine.webkit < 412){
  safariVersion = 1.3;
 } else {
  safariVersion = 2;
 }
 browser.safari = browser.ver = safariVersion; 
 }
} else if (/KHTML\/(\S+)/.test(ua) || /Konquersor\/([^;]+)/.test(ua)){
 engine.ver = browser.ver = RegExp["$1"];
 engine.khtml = browser.kong = paresFloat(engine.ver); 
} else if (/rv:([^\)]+)\) Gecko\/\d{8}/.test(ua)){
 engine.ver = RegExp["$1"]
 engine.gecko = parseFloat(engine.ver);
 //确定是不是Firefox
 if (/Firefox\/(\S+)/.test(ua)){
 browser.ver = RegExp["$1"];
 browser.firefox = pareseFloat(browser.ver);
 }
} else if(/MSIE([^;]+)/.test(ua)){
 browser.ver = RegExp["$1"];
 browser.firefox = parseFloat(browser.ver);
}
//检测浏览器
browser.ie = engine.ie;
browser.opera = engine.opera;
//检测平台
var p = navigator.platform;
system.win = p.indexOf("Win") == 0;
system.mac = p.indexOf("Mac") == 0;
system.x11 = (p == "X11") || (p.indexOf("Linux") == 0);
//检测Windows操作系统
if (system.win){
 if (/Win(&#63;:doms)&#63;([^do]{2})\s&#63;(\d+\.\d+)&#63;/.test(ua)){
 if (RegExp["$1"] == "NT"){
  switch(RegExp["$2"]){
  case "5.0":
   system.win = "2000";
   break;
  case "5.1":
   system.win = "XP";
   break;
  case "6.0":
   system.win = "Vista";
   break;
  default  :
   system.win = "NT";
   break;  
  }
 } else if (RegExp["$1"]){
  system.win = "ME";
 } else {
  system.win = RegExp["$1"];
 }
 }
}
//移动设备
system.iphone = ua.indexOf("iPhone") > -1;
system.ipod   = ua.indexOf("iPod") > -1;
system.nokiaN = ua.indexOf("NokiaN") > -1;
system.winMobile = (system.win == "CE");
system.macMobile = (system.iphone || system.ipod);
//游戏系统
system.wii = ua.indexOf("Wii") > -1;
system.ps = /playstation/i.test(ua);
//返回这些对象
return {
 engine: engine,
 browser: browser,
 system: system
};
}()