判断浏览器和操作系统的js

var sUserAgent = navigator.userAgent;

var fAppVersion = parseFloat(navigator.appVersion);

function compareVersions(sVersion1, sVersion2) {

var aVersion1 = sVersion1.split(".");

var aVersion2 = sVersion2.split(".");

if (aVersion1.length > aVersion2.length) {

for (var i=0; i < aVersion1.length - aVersion2.length; i=i+1) {

aVersion2.push("0");

}

} else if (aVersion1.length < aVersion2.length) {

for (var i=0; i < aVersion2.length - aVersion1.length; i=i+1) {

aVersion1.push("0");

}

}

for (var i=0; i < aVersion1.length; i=i+1) {

if (aVersion1 < aVersion2) {

return -1;

} else if (aVersion1 > aVersion2) {

return 1;

}

}

return 0;

}

var isOpera = sUserAgent.indexOf("Opera") > -1;

var isMinOpera4 = isMinOpera5 = isMinOpera6 = isMinOpera7 = isMinOpera7_5 = false;

if (isOpera) {

var fOperaVersion;

if(navigator.appName == "Opera") {

fOperaVersion = fAppVersion;

} else {

var reOperaVersion = new RegExp("Opera (//d+//.//d+)");

reOperaVersion.test(sUserAgent);

fOperaVersion = parseFloat(RegExp["$1"]);

}

isMinOpera4 = fOperaVersion >= 4;

isMinOpera5 = fOperaVersion >= 5;

isMinOpera6 = fOperaVersion >= 6;

isMinOpera7 = fOperaVersion >= 7;

isMinOpera7_5 = fOperaVersion >= 7.5;

}

var isKHTML = sUserAgent.indexOf("KHTML") > -1

|| sUserAgent.indexOf("Konqueror") > -1

|| sUserAgent.indexOf("AppleWebKit") > -1;

var isMinSafari1 = isMinSafari1_2 = false;

var isMinKonq2_2 = isMinKonq3 = isMinKonq3_1 = isMinKonq3_2 = false;

if (isKHTML) {

isSafari = sUserAgent.indexOf("AppleWebKit") > -1;

isKonq = sUserAgent.indexOf("Konqueror") > -1;

if (isSafari) {

var reAppleWebKit = new RegExp("AppleWebKit///(//d+(?://.//d*)?)");

reAppleWebKit.test(sUserAgent);

var fAppleWebKitVersion = parseFloat(RegExp["$1"]);

isMinSafari1 = fAppleWebKitVersion >= 85;

isMinSafari1_2 = fAppleWebKitVersion >= 124;

} else if (isKonq) {

var reKonq = new RegExp("Konqueror///(//d+(?://.//d+(?://.//d)?)?)");

reKonq.test(sUserAgent);

isMinKonq2_2 = compareVersions(RegExp["$1"], "2.2") >= 0;

isMinKonq3 = compareVersions(RegExp["$1"], "3.0") >= 0;

isMinKonq3_1 = compareVersions(RegExp["$1"], "3.1") >= 0;

isMinKonq3_2 = compareVersions(RegExp["$1"], "3.2") >= 0;

}

}

var isIE = sUserAgent.indexOf("compatible") > -1

& sUserAgent.indexOf("MSIE") > -1

& !isOpera;

var isMinIE4 = isMinIE5 = isMinIE5_5 = isMinIE6 = isMinIE7 = false;

if (isIE) {

var reIE = new RegExp("MSIE (//d+//.//d+);");

reIE.test(sUserAgent);

var fIEVersion = parseFloat(RegExp["$1"]);

isMinIE4 = fIEVersion >= 4;

isMinIE5 = fIEVersion >= 5;

isMinIE5_5 = fIEVersion >= 5.5;

isMinIE6 = fIEVersion >= 6.0;

isMinIE7 = fIEVersion >= 7.0;

}

var isMoz = sUserAgent.indexOf("Gecko") > -1

& !isKHTML;

var isMinMoz1 = sMinMoz1_4 = isMinMoz1_5 = isMinMozl_5_1 = false;

if (isMoz) {

var reMoz = new RegExp("rv//d+//.//d+(?://.//d+)?)");

reMoz.test(sUserAgent);

isMinMoz1 = compareVersions(RegExp["$1"], "1.0") >= 0;

isMinMoz1_4 = compareVersions(RegExp["$1"], "1.4") >= 0;

isMinMoz1_5 = compareVersions(RegExp["$1"], "1.5") >= 0;

isMinMoz2 = compareVersions(RegExp["$1"], "1.8") >=0;

}

var isNS4 = !isIE & !isOpera && !isMoz && !isKHTML

& (sUserAgent.indexOf("Mozilla") == 0)

& (navigator.appName == "Netscape")

& (fAppVersion >= 4.0 && fAppVersion < 5.0);

var isMinNS4 = isMinNS4_5 = isMinNS4_7 = isMinNS4_8 = false;

if (isNS4) {

isMinNS4 = true;

isMinNS4_5 = fAppVersion >= 4.5;

isMinNS4_7 = fAppVersion >= 4.7;

isMinNS4_8 = fAppVersion >= 4.8;

}

var isWin = (navigator.platform == "Win32") || (navigator.platform == "Windows");

var isMac = (navigator.platform == "Mac68K") || (navigator.platform == "MacPPC")

|| (navigator.platform == "Macintosh");

var isUnix = (navigator.platform == "X11") & !isWin && !isMac;

var isWin95 = isWin98 = isWinNT4 = isWin2K = isWinME = isWinXP = isWin03 = false;

var isMac68K = isMacPPC = false;

var isSunOS = isMinSunOS4 = isMinSunOS5 = isMinSunOS5_5 = false;

if (isWin) {

isWin95 = sUserAgent.indexOf("Win95") > -1

|| sUserAgent.indexOf("Windows 95") > -1;

isWin98 = sUserAgent.indexOf("Win98") > -1

|| sUserAgent.indexOf("Windows 98") > -1;

isWinME = sUserAgent.indexOf("Win 9x 4.90") > -1

|| sUserAgent.indexOf("Windows ME") > -1;

isWin2K = sUserAgent.indexOf("Windows NT 5.0") > -1

|| sUserAgent.indexOf("Windows 2000") > -1;

isWinXP = sUserAgent.indexOf("Windows NT 5.1") > -1

|| sUserAgent.indexOf("Windows XP") > -1;

isWinNT4 = sUserAgent.indexOf("WinNT") > -1

|| sUserAgent.indexOf("Windows NT") > -1

|| sUserAgent.indexOf("WinNT4.0") > -1

|| sUserAgent.indexOf("Windows NT 4.0") > -1

& (!isWinME && !isWin2K && !isWinXP);

isWin03 = sUserAgent.intexOf("Windows NT 5.2") > -1

}

if (isMac) {

isMac68K = sUserAgent.indexOf("Mac_68000") > -1

|| sUserAgent.indexOf("68K") > -1;

isMacPPC = sUserAgent.indexOf("Mac_PowerPC") > -1

|| sUserAgent.indexOf("PC") > -1;

}

if (isUnix) {

isSunOS = sUserAgent.indexOf("SunOS") > -1;

if (isSunOS) {

var reSunOS = new RegExp("SunOS (//d+//.//d+(?://.//d+)?)");

reSunOS.test(sUserAgent);

isMinSunOS4 = compareVersions(RegExp["$1"], "4.0") >= 0;

isMinSunOS5 = compareVersions(RegExp["$1"], "5.0") >= 0;

isMinSunOS5_5 = compareVersions(RegExp["$1"], "5.5") >= 0;

}

}