Code for jquery to determine the browser type

In Jquery, navigator. userAgent. indexOf is used to determine the browser type and perform some processing. It is recommended that you learn about Jquery and learn about the idea.

Main usage: $. browser. ['browser keyword ']
Copy codeThe Code is as follows:
$ (Function (){
If ($. browser. msie ){
Alert ("this is msie ");
} Else if ($. browser. safari ){
Alert ("this is safari! ");
} Else if ($. browser. mozilla ){
Alert ("this is mozilla! ");
} Else if ($. browser. opera ){
Alert ("this is opera ");
} Else {
Alert ("I don't konw! ");
}

Let's take a look at the jQuery source code:
Copy codeThe Code is as follows:
Var userAgent = navigator. userAgent. toLowerCase ();
// Figure out what browser is being used
JQuery. browser = {
Version: (userAgent. match (/. + (? : Rv | it | ra | ie) [\/:] ([\ d.] +)/) | []) [1],
Safari:/webkit/. test (userAgent ),
Opera:/opera/. test (userAgent ),
Msie:/msie/. test (userAgent )&&! /Opera/. test (userAgent ),
Mozilla:/mozilla/. test (userAgent )&&! /(Compatible | webkit)/. test (userAgent)
};

Jquery uses regular expressions to match userAgent to determine the browser type and version.
Version --- browser version
Msie ---- IE browser (Microsoft Internet Explorer)
Mozilla-Firefox
Opera-operabrowser

How can we determine whether the current browser is IE6?

Copy codeThe Code is as follows:
If ($. browser. msie & ($. browser. version = "6.0 ")&&! $. Support. style ){
Alert ("ie6 ");
}

Similarly, Jquery checks whether the browser is IE7.
Copy codeThe Code is as follows:
If ($. browser. msie & ($. browser. version = "7.0 ")){
Alert ("ie7 ");
}

If you do not want to use Jquery, you can modify the code to use the Js Code:
Copy codeThe Code is as follows:
Var userAgent = navigator. userAgent. toLowerCase ();
Browser = {
Version: (userAgent. match (/. + (? : Rv | it | ra | ie) [\/:] ([\ d.] +)/) | [0, '0']) [1],
Safari:/webkit/. test (userAgent ),
Opera:/opera/. test (userAgent ),
Msie:/msie/. test (userAgent )&&! /Opera/. test (userAgent ),
Mozilla:/mozilla/. test (userAgent )&&! /(Compatible | webkit)/. test (userAgent)
}

The call is the same as that of jquery, except that the $ symbol is removed.

To determine the version of IE, we recommend that you use the conditional expression of IE to write JavaScript code.
Copy codeThe Code is as follows:
<! -- [If IE]>
<Script type = "text/javascript">
Alert ("ie ");
</Script>
<! [Endif] -->
<! -- [If IE 6]>
<Script type = "text/javascript">
Alert ("ie6 ");
</Script>
<! [Endif] -->
<! -- [If IE 7]>
<Script type = "text/javascript">
Alert ("ie7 ");
</Script>
<! [Endif] -->

This is more accurate than we manually use $. browser to determine the IE version, and we do not need to record the use of jquery's browser.