javascript - 在替换第 n 个子字符串 Google 脚本中将变量添加到 RegEx

Question

我正在尝试向函数调用添加变量

原来的函数来自这里 Find and replace nth occurrence of [bracketed] expression in string

var s = "HELLO, WORLD!";
var nth = 0;
s = s.replace(/L/g, function (match, i, original) {
nth++;
return (nth === 2) ? "M" : match;
});
alert(s); // "HELMO, WORLD!";

我正在尝试这样做

function ReplaceNth_n() {

Logger.log(ReplaceNth("HELLO, WORLD!", "L", "M"))

}  

function ReplaceNth(strSearch,search_for, replace_with) {
   var nth = 0;
   strSearch = strSearch.replace(/search_for/g, function (match, i, original) {
   nth++;
   return (nth === 2) ? replace_with : match;
   });
  return strSearch 
} 

这部分失败；更换

s = s.replace(/L/g, 函数(匹配, i, 原始)

与

strSearch = strSearch.replace(/search_for/g, 函数(匹配、i、原始)

我尝试过各种变化

strSearch = strSearch.replace('/'+ search_for +'/g', function (match, i, original)

但不知道如何做到这一点

谢谢

Answer 1

您可以使用new RegExp从变量创建正则表达式。以下代码应该可以工作:

function ReplaceNth_n() {

    Logger.log(ReplaceNth("HELLO, WORLD!", "L", "M"))

}  

function ReplaceNth(strSearch,search_for, replace_with) {
    var nth = 0;
    strSearch = strSearch.replace(new RegExp(search_for, 'g'), function (match, i, original) {
        nth++;
        return (nth === 2) ? replace_with : match;
    });
    return strSearch 
}

ReplaceNth_n() //output 'HELMO, WORLD!'

请正确格式化您的代码部分...