这让我有了火狐的版本，

    let versionNumber = parseInt(window.navigator.userAgent.match(/Firefox\/([0- 
    9]+)\./)[1]);

这让我有了火狐的版本，

    let versionNumber = parseInt(window.navigator.userAgent.match(/Firefox\/([0- 
    9]+)\./)[1]);

var ua = navigator.userAgent;

if (/Firefox\//.test(ua))
   var Firefox = /Firefox\/([0-9\.A-z]+)/.exec(ua)[1];

看看navigator。userAgent - Firefox/xxx.xxx. xxx。XXX是在结尾指定的。

var nVer = navigator.appVersion;
var nAgt = navigator.userAgent;
var browserName = navigator.appName;
var fullVersion = '' + parseFloat(navigator.appVersion);
var majorVersion = parseInt(navigator.appVersion, 10);
var nameOffset, verOffset, ix;

// In Opera 15+, the true version is after "OPR/" 
if ((verOffset = nAgt.indexOf("OPR/")) != -1) {
    browserName = "Opera";
    fullVersion = nAgt.substring(verOffset + 4);
}
// In older Opera, the true version is after "Opera" or after "Version"
else if ((verOffset = nAgt.indexOf("Opera")) != -1) {
    browserName = "Opera";
    fullVersion = nAgt.substring(verOffset + 6);
    if ((verOffset = nAgt.indexOf("Version")) != -1)
        fullVersion = nAgt.substring(verOffset + 8);
}
// In MSIE, the true version is after "MSIE" in userAgent
else if ((verOffset = nAgt.indexOf("MSIE")) != -1) {
    browserName = "Microsoft Internet Explorer";
    fullVersion = nAgt.substring(verOffset + 5);
}
// In Chrome, the true version is after "Chrome" 
else if ((verOffset = nAgt.indexOf("Chrome")) != -1) {
    browserName = "Google Chrome";
    fullVersion = nAgt.substring(verOffset + 7);
}
// In Safari, the true version is after "Safari" or after "Version" 
else if ((verOffset = nAgt.indexOf("Safari")) != -1) {
    browserName = "Safari";
    fullVersion = nAgt.substring(verOffset + 7);
    if ((verOffset = nAgt.indexOf("Version")) != -1)
        fullVersion = nAgt.substring(verOffset + 8);
}
// In Firefox, the true version is after "Firefox" 
else if ((verOffset = nAgt.indexOf("Firefox")) != -1) {
    browserName = "Mozilla Firefox";
    fullVersion = nAgt.substring(verOffset + 8);
}
// In most other browsers, "name/version" is at the end of userAgent 
else if ((nameOffset = nAgt.lastIndexOf(' ') + 1) < (verOffset = nAgt.lastIndexOf('/'))) {
    browserName = nAgt.substring(nameOffset, verOffset);
    fullVersion = nAgt.substring(verOffset + 1);
    if (browserName.toLowerCase() == browserName.toUpperCase()) {
        browserName = navigator.appName;
    }
}
// trim the fullVersion string at semicolon/space if present
if ((ix = fullVersion.indexOf(';')) != -1) fullVersion = fullVersion.substring(0, ix);
if ((ix = fullVersion.indexOf(' ')) != -1) fullVersion = fullVersion.substring(0, ix);

majorVersion = parseInt('' + fullVersion, 10);
if (isNaN(majorVersion)) {
    fullVersion = '' + parseFloat(navigator.appVersion);
    majorVersion = parseInt(navigator.appVersion, 10);
}

这里有更好的兼容性@kennebec snippet; 将返回浏览器名称和版本(返回72而不是72.0.3626.96)。

在Safari, Chrome, Opera, Firefox, IE, Edge, UCBrowser上测试，也在移动设备上测试。

function browser() {
    var userAgent = navigator.userAgent,
        match = userAgent.match(/(opera|chrome|crios|safari|ucbrowser|firefox|msie|trident(?=\/))\/?\s*(\d+)/i) || [],
        result = {},
        tem;

    if (/trident/i.test(match[1])) {
        tem = /\brv[ :]+(\d+)/g.exec(userAgent) || [];
        result.name = "Internet Explorer";
    } else if (match[1] === "Chrome") {
        tem = userAgent.match(/\b(OPR|Edge)\/(\d+)/);

        if (tem && tem[1]) {
            result.name = tem[0].indexOf("Edge") === 0 ? "Edge" : "Opera";
        }
    }
    if (!result.name) {
        tem = userAgent.match(/version\/(\d+)/i); // iOS support
        result.name = match[0].replace(/\/.*/, "");

        if (result.name.indexOf("MSIE") === 0) {
            result.name = "Internet Explorer";
        }
        if (userAgent.match("CriOS")) {
            result.name = "Chrome";
        }

    }
    if (tem && tem.length) {
        match[match.length - 1] = tem[tem.length - 1];
    }

    result.version = Number(match[match.length - 1]);

    return result;
}