JS中实现replaceAll的方法

JS中实现replaceAll的方法

原文：
http://fuleonardo.iteye.com/blog/339749

第一次发现JavaScript中replace() 方法如果直接用str.replace("-","!") 只会替换第一个匹配的字符.
而str.replace(/\-/g,"!")则可以全部替换掉匹配的字符(g为全局标志)。

replace()
The replace() method returns the string that results when you replace text matching its first argument
(a regular expression) with the text of the second argument (a string).
If the g (global) flag is not set in the regular expression declaration, this method replaces only the first
occurrence of the pattern. For example,

var s = "Hello. Regexps are fun.";s = s.replace(/\./, "!"); // replace first period with an exclamation pointalert(s);

produces the string “Hello! Regexps are fun.” Including the g flag will cause the interpreter to
perform a global replace, finding and replacing every matching substring. For example,

var s = "Hello. Regexps are fun.";s = s.replace(/\./g, "!"); // replace all periods with exclamation pointsalert(s);

yields this result: “Hello! Regexps are fun!”

所以可以用以下几种方式.：
string.replace(/reallyDo/g, replaceWith);
string.replace(new RegExp(reallyDo, 'g'), replaceWith);

string：字符串表达式包含要替代的子字符串。
reallyDo：被搜索的子字符串。
replaceWith：用于替换的子字符串。

 

< script type = " text/javascript " >
String.prototype.replaceAll  =   function (reallyDo, replaceWith, ignoreCase)  {
    if (!RegExp.prototype.isPrototypeOf(reallyDo)) {
        return this.replace(new RegExp(reallyDo, (ignoreCase ? "gi": "g")), replaceWith);
    } else {
        return this.replace(reallyDo, replaceWith);
    }
}
</ script >

 

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