比较全的使用JavaScript获取当前网页运行环境的明细，比如操作系统类型，设备类型alert(JSON.var us

<html>
<script>

var OS = {
		"WINDOWS": "win",
		"MACINTOSH": "mac",
		"LINUX": "linux",
		"IOS": "iOS",
		"ANDROID": "Android",
		"BLACKBERRY": "bb",
		"WINDOWS_PHONE": "winphone"
	};

var result = getOS();

alert(JSON.stringify(result));

function getOS() { 

		var userAgent = navigator.userAgent;

		var platform, result;

		function getDesktopOS(){
			var pf = navigator.platform;
			if (pf.indexOf("Win") != -1 ) { // 说明当前是Windows操作系统
				var rVersion = /Windows NT (\d+).(\d)/i;
				var uaResult = userAgent.match(rVersion);
				var sVersionStr = "";
				if (uaResult[1] == "6") {
					if (uaResult[2] == 1) {
						sVersionStr = "7"; // 说明当前运行在Windows 7 中
					} else if (uaResult[2] > 1) {
						sVersionStr = "8"; // 说明当前运行在Windows 8 中
					}
				} else {
					sVersionStr = uaResult[1];
				}
				return {"name": OS.WINDOWS, "versionStr": sVersionStr};

			} else if (pf.indexOf("Mac") != -1) {
				return {"name": OS.MACINTOSH, "versionStr": ""}; // Macintosh操作系统
			} else if (pf.indexOf("Linux") != -1) {
				return {"name": OS.LINUX, "versionStr": ""}; // 说明当前运行在Linux操作系统
			}
			return null;
		}

		platform = /Windows Phone (?:OS )?([\d.]*)/; // windows phone的正则表达式
		result = userAgent.match(platform);
		if (result) {
			return ({"name": OS.WINDOWS_PHONE, "versionStr": result[1]});
		}

		// BlackBerry 10
		if (userAgent.indexOf("(BB10;") > 0) { 
			platform = /\sVersion\/([\d.]+)\s/; // BlackBerry的regular expression
			result = userAgent.match(platform);
			if (result) {
				return {"name": OS.BLACKBERRY, "versionStr": result[1]};
			} else {
				return {"name": OS.BLACKBERRY, "versionStr": '10'};
			}
		}

		// iOS, Android, BlackBerry 6.0+:
		platform = /\(([a-zA-Z ]+);\s(?:[U]?[;]?)([\D]+)((?:[\d._]*))(?:.*[\)][^\d]*)([\d.]*)\s/;
		result = userAgent.match(platform);
		if (result) {
			var appleDevices = /iPhone|iPad|iPod/;
			var bbDevices = /PlayBook|BlackBerry/;
			if (result[0].match(appleDevices)) {
				result[3] = result[3].replace(/_/g, ".");
				return ({"name": OS.IOS, "versionStr": result[3]}); // iOS操作系统
			} else if (result[2].match(/Android/)) {
				result[2] = result[2].replace(/\s/g, "");
				return ({"name": OS.ANDROID, "versionStr": result[3]}); // Android操作系统
			} else if (result[0].match(bbDevices)) {
				return ({"name": OS.BLACKBERRY, "versionStr": result[4]}); // Blackberry
			}
		}

		//Android平台上的Firefox浏览器
		platform = /\((Android)[\s]?([\d][.\d]*)?;.*Firefox\/[\d][.\d]*/;
		result = userAgent.match(platform);
		if (result) {
			return ({"name": OS.ANDROID, "versionStr": result.length == 3 ? result[2] : ""});
		}

		// Desktop
		return getDesktopOS();
	}
</script>
</html>