javascript中使用replaceAll()函数实现字符替换的方法

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>