js的判断浏览器，判断是不是安卓或IOS

 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,
					safari: 0,
					konq: 0,
					opera: 0,
					chrome: 0,
					//具体的版本号
					ver: null
				};
				//平台、设备和操作系统
				var system = {
					win: false,
					mac: false,
					x11: false,
					//移动设备
					iphone: false,
					ipod: false,
					ipad: false,
					ios: false,
					android: false,
					nokiaN: false,
					winMobile: false,
					//游戏系统
					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) || /Konqueror\/([^;]+)/.test(ua)) {
					engine.ver = browser.ver = RegExp["$1"];
					engine.khtml = browser.konq = parseFloat(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 = parseFloat(browser.ver);
					}
				} else if(/MSIE ([^;]+)/.test(ua)) {
					engine.ver = browser.ver = RegExp["$1"];
					engine.ie = browser.ie = parseFloat(engine.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(?:dows )?([^do]{2})\s?(\d+\.\d+)?/.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;
								case "6.1":
									system.win = "7";
									break;
								default:
									system.win = "NT";
									break;
							}
						} else if(RegExp["$1"] == "9x") {
							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.ipad = ua.indexOf("iPad") > -1;
				system.nokiaN = ua.indexOf("NokiaN") > -1;
				//windows mobile
				if(system.win == "CE") {
					system.winMobile = system.win;
				} else if(system.win == "Ph") {
					if(/Windows Phone OS (\d+.\d+)/.test(ua)) {;
						system.win = "Phone";
						system.winMobile = parseFloat(RegExp["$1"]);
					}
				}
				//检测 iOS 版本
				if(system.mac && ua.indexOf("Mobile") > -1) {
					if(/CPU (?:iPhone )?OS (\d+_\d+)/.test(ua)) {
						system.ios = parseFloat(RegExp.$1.replace("_", "."));
					} else {
						system.ios = 2; //不能真正检测出来，所以只能猜测
					}
				}
				//检测 Android 版本
				if(/Android (\d+\.\d+)/.test(ua)) {
					system.android = parseFloat(RegExp.$1);
				}
				//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
				};
			}();
			console.log("========>>>client", client);