Instructions on CSS operations in jquery

I just read jquery's Source code Among them, the Operation ideas about CSS and classname are really good and worth learning.
For details about jquery. classname. the definition part of has is implemented using regular expressions. In fact, if you directly use the indexof method of the string object in Javascript for processing, it is more efficient than using regular expressions. CopyCode The Code is as follows: the definition of jquery. classname. Has can be improved:
Has: function (T, C ){
T = T. classname | T;
T = "" + T + "";
C = "" + C + "";
Return T. indexof (c)>-1;
}

The operations on CSS and classname in the original code are excerpted as follows:Copy codeThe Code is as follows: classname :{
// Internal only, use addclass ("class ")
Add: function (ELEM, c ){
Jquery. Each (C. Split (/\ s +/), function (I, cur ){
If (! Jquery. classname. Has (ELEM. classname, cur ))
ELEM. classname + = (ELEM. classname? "": "") + Cur;
});
},

// Internal only, use removeclass ("class ")
Remove: function (ELEM, c ){
ELEM. classname = C?
Jquery. grep (ELEM. classname. Split (/\ s +/), function (cur ){
Return! Jquery. classname. Has (C, cur );
}). Join (""):"";
},

// Internal only, use is (". Class ")
Has: function (T, C ){
T = T. classname | T;
// Escape RegEx characters
C = C. Replace (/([\. \ + \*\? \ [\ ^ \] \ $ \ (\) \ {\}\= \! \<\>\|\:])/G, "\\$ 1 ");
Return T & New Regexp ("(^ | \ s)" + C + "(\ s | $)"). Test (t );
}
},
Swap: function (E, O, F ){
For (var I in O ){
E. Style ["old" + I] = E. Style [I];
E. Style [I] = O [I];
}
F. Apply (E, []);
For (var I in O)
E. Style [I] = E. Style ["old" + I];
},

CSS: function (E, P ){
If (P = "height" | P = "width "){
VaR old = {}, oheight, owidth, D = ["TOP", "bottom", "right", "Left"];

Jquery. Each (D, function (){
Old ["padding" + This] = 0;
Old ["border" + This + "width"] = 0;
});

Jquery. Swap (E, old, function (){
If (jquery.css (E, "display ")! = "NONE "){
Oheight = E. offsetheight;
Owidth = E. offsetwidth;
} Else {
E = jquery (E. clonenode (true ))
. Find (": Radio"). removeattr ("checked"). End ()
. CSS ({
Visibility: "hidden", position: "absolute", display: "Block", right: "0", left: "0"
}). Appendto (E. parentnode) [0];

VaR parpos = jquery.css (E. parentnode, "position ");
If (parpos = "" | parpos = "static ")
E. parentnode. style. Position = "relative ";

Oheight = E. clientheight;
Owidth = E. clientwidth;

If (parpos = "" | parpos = "static ")
E. parentnode. style. Position = "static ";

E. parentnode. removechild (E );
}
});

Return P = "height "? Oheight: owidth;
}

Return jquery. curcss (E, P );
},

Curcss: function (ELEM, prop, force ){
VaR ret;

If (prop = "opacity" & jquery. browser. MSIE)
Return jquery. ATTR (ELEM. style, "opacity ");

If (prop = "float" | prop = "cssfloat ")
Prop = jquery. browser. MSIE? "Stylefloat": "cssfloat ";

If (! Force & ELEM. Style [prop])
Ret = ELEM. Style [prop];

Else if (document. defaultview & document. defaultview. getcomputedstyle ){

If (prop = "cssfloat" | prop = "stylefloat ")
Prop = "float ";

Prop = prop. Replace (/([A-Z])/g, "-$1"). tolowercase ();
VaR cur = Document. defaultview. getcomputedstyle (ELEM, null );

If (cur)
Ret = cur. getpropertyvalue (PROP );
Else if (prop = "display ")
Ret = "NONE ";
Else
Jquery. Swap (ELEM, {display: "Block"}, function (){
VaR c = Document. defaultview. getcomputedstyle (this ,"");
Ret = C & C. getpropertyvalue (PROP) | "";
});

} Else if (ELEM. currentstyle ){

VaR newprop = prop. Replace (/\-(\ W)/g, function (M, c) {return C. touppercase ();});
Ret = ELEM. currentstyle [prop] | ELEM. currentstyle [newprop];

}

Return ret;
},

Appendix:
Jquery Official Website: http://jquery.com/
Jquery source code download: http://docs.jquery.com/Downloading_jQuery
Jquery API documentation: http://docs.jquery.com/Main_Page
Jquery China: http://jquery.org.cn/
Visualjquery.com: http://visualjquery.com/