第一次發(fā)現(xiàn)JavaScript中replace() 方法如果直接用str.replace("-","!") 只會替換第一個匹配的字符.
而str.replace(/\-/g,"!")則可以全部替換掉匹配的字符(g為全局標(biāo)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!”

所以可以用以下幾種方式：

string.replace(/reallyDo/g, replaceWith);

string.replace(new RegExp(reallyDo, 'g'), replaceWith);

string：字符串表達(dá)式包含要替代的子字符串。
reallyDo：被搜索的子字符串。

replaceWith：用于替換的子字符串。

Js代碼

<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> 

以上這篇js替換字符串中所有指定的字符(實(shí)現(xiàn)代碼)就是小編分享給大家的全部內(nèi)容了，希望能給大家一個參考，也希望大家多多支持腳本之家。