javascript中使用replaceAll()函数实现字符替换的方法
作者:mdxy-dxy 时间:2024-04-10 16:18:47
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>
补充
我们在Java中可以使用replaceAll()方法对字符串进行批量替换,但在JS中replaceAll()方法是undefined,JS中只存在replace()方法,因此我们可以自己封装JS中replaceAll()方法供我们便捷使用。
一、使用replace()方法进行替换
定义一个字符串:
var str = "hello world";
使用replace()方法将字符串中的字母"l"替换成"i",原始做法:
console.log(str.replace("l","i"));
输出:
“heilo world”
需要执行三次,非常不方便;
二、使用replaceAll()方法替换
封装replaceAll()方法:
String.prototype.replaceAll = function(s1, s2) {
return this.replace(new RegExp(s1, "gm"), s2);
}
定义一个字符串:
var str = "hello world";
使用replaceAll()方法进行批量替换:
console.log(str.replaceAll("l", "i"));
输出:
“heiio worid”
只需要执行一次,就完成了全部替换需求。