Javascript - detecting browser version

Question

I know this is not the most reliable way, but I don't really have many other choices. I essentially need to detect what browser and version visits my website. If it is a certain browser/version, it will display a message. This is for the TLS issue, whereby certain browser versions will not display a https page.

Anyways, at the moment I have something like the following

function getBrowserInfo()
{
 var ua = navigator.userAgent, tem,
 M = ua.match(/(opera|chrome|safari|firefox|msie|trident(?=\/))\/?\s*(\d+)/i) || [];
 if(/trident/i.test(M[1]))
 {
 tem= /\brv[ :]+(\d+)/g.exec(ua) || [];
 return 'IE '+(tem[1] || '');
 }
 if(M[1]=== 'Chrome')
 {
 tem= ua.match(/\b(OPR|Edge)\/(\d+)/);
 if(tem!= null) return tem.slice(1).join(' ').replace('OPR', 'Opera');
 }
 M = M[2]? [M[1], M[2]]: [navigator.appName, navigator.appVersion, '-?'];
 if((tem= ua.match(/version\/(\d+)/i))!= null)
 M.splice(1, 1, tem[1]);
 return M.join(' ');
}
var browserInfo = getBrowserInfo();
browserInfo = browserInfo.split(" ");
$(function () {
 alert(browserInfo);
 if(browserInfo[0] == 'Firefox' && browserInfo[1] < 27) {
 alert("Firefox");
 }
 if(browserInfo[0] == 'Chrome' && browserInfo[1] < 22) {
 alert("Chrome");
 }
 if(browserInfo[0] == 'IE' && browserInfo[1] < 11) {
 alert("IE");
 }
 if(browserInfo[0] == 'Safari' && browserInfo[1] < 11) {
 alert("Safari");
 }
 if(browserInfo[0] == 'Opera' && browserInfo[1] < 14) {
 alert("Safari");
 }
});

One thing that concerns me is the splitting of the string, incase a browser returns a different format. Additionally, I think all of these if statements are redundant, but I cant think of a more efficient way to do this.

Essentially, I am looking for advice as to the best way to detect a browser, and its version, so I can display a custom message for that browser.

Thanks

• Stphane: Possible duplicate of How to detect Safari, Chrome, IE, Firefox and Opera browser?
• Sami: Or possible duplicate of How can you detect the version of a browser?
• katie hudson: These links help a lot. My question really comes down to the effeciency, as I do not think all of these if statements are the best, Is there any way to improve this?

Answer 1

It seems like you're using jQuery. You could detect the browser version using $.browser, but that feature is deprecated starting from version 1.9.1.

I would advise using this jQuery-plugin, which supports browser type & version detection: https://github.com/gabceb/jquery-browser-plugin

Using this plugin, you can test for browser vendors using this code:

if($.browser.msie) {
 alert('ie');
}
if($.browser.mozilla) {
 alert('firefox');
}
...

If you would like to check for the version of the browser, you could use this code:

$.browser.version

Answer 2

Return ie version using javascript

function getInternetExplorerVersion()
 // Returns the version of Internet Explorer or a -1
 // (indicating the use of another browser).
{
 var rv = -1; // Return value assumes failure.
 if (navigator.appName == 'Microsoft Internet Explorer') 
{
 var ua = navigator.userAgent;
 var re = new RegExp("MSIE ([0-9]{1,}[\.0-9]{0,})");
 if (re.exec(ua) != null)
 rv = parseFloat(RegExp.1ドル);
 }
 return rv;
}