Learn string.replace() function from jQuery.camelCase()_javascript skills-JS Tutorial-php.cn

Learn string.replace() function from jQuery.camelCase()_javascript skills

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Release： 2016-05-16 18:02:18

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Function
The function of the camelCase function is to convert the form background-color into camel case notation: backgroundColor.
This function is used in jQuery’s data function and many functions involving css.

Implementation of jQuery

Copy code The code is as follows:

 
//Regular Match
rdashAlpha = /-([a-z])/ig, 
// Callback function when camelCase replaces string 
fcamelCase = function( all, letter ) { 
return letter.toUpperCase() ; 
}, 
... 
camelCase: function( string ) { 
return string.replace( rdashAlpha, fcamelCase ); 
}, 

this The function itself is not difficult, it just calls the replace method of the String object. But in the spirit of learning, I still studied the replacement method.
Data reference: https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/String/replace

String.replace() syntax
str.replace(regexp|substr, newSubStr|function[, Non-standard flags]);

String.replace() parameter description
regexp: one for searching regular expressions
substr: one for searching for strings
newSubStr: a new string for replacement
function: a callback function, the return value of the function is used to replace the original matching string
flags: non-standard, similar to i, g, m of RegExp (Ignore case, search globally, match multiple lines)

Specify a string as the replacement object
You can use the following pattern in the string used for replacement:
$$ => Insert a $
$& => Insert matching substring
$` => Insert all characters before matching substring
$' => Insert all characters after matching substring
$n / $nn => This mode is only valid when the first parameter of the replace() method is RegExp and the regular expression contains parentheses.

Specify function as replacement object
Typical replacement function: function(str,p1,p2,offset,s){}
Parameter description:
str: matching string (similar $&)
p1,p2,...: This mode is only valid when the first parameter of the replace() method is RegExp and the regular expression contains parentheses. (Similar to $n / $nn)
offset: the offset of the matching substring
s: the string used for search

Get the camel case representation of the CSS property

Copy code The code is as follows:

 
String.prototype.camelCase=function(){ 
 //all is the matching substring, and letter is p1, because [a-z] has parentheses 
return this.replace(/-([a-z])/ig,function( all, letter,offset,s ) { 
return letter.toUpperCase(); 
}); 
}; 
var cssText = 'h2n{n border-bottom:1px solid #eee;n background-color:#bbb;n }'; 
var newstr = cssText.camelCase(); 

Exchange the position of the matching string

Copy code The code is as follows:

 
var re = /(w )s(w )/; 
var str = "John Smith"; 
var newstr = str.replace(re, "$2, $1"); 