使用js替换字符串中所有指定字符的实现方法

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。

js代码

<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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