將在 n(2nd argumanet) 次后從向后插入第一個引數的函式
const string = "abcdefg";
const backWardInsert = (str, num) => {
// Do the stuffs
// Here is what I"ve tried
const newStr = string.replace(/(.{3})/g, "$-1$");
return newStr;
};
const result = backWardInsert("$", 3);
// result should be "a$bcd$efg"
console.log(result);uj5u.com熱心網友回復：
也許這就是你想要的
const string = "abcdefg";
const backWardInsert = (str, num) => {
const regex = new RegExp(`(.{${num}})`, "gi");
const newStr = string
.split("")
.reverse()
.join("")
.replace(regex, "$1" str)
.split("")
.reverse()
.join("");
return newStr;
};
const result = backWardInsert("$", 3);
console.log(result);uj5u.com熱心網友回復：
您可以采取積極的前瞻性并添加美元符號
const string = "abcdefg";
const backWardInsert = (str, num) => {
return string.replace(new RegExp(`.{1,${num}}(?=(.{${num}}) $)`, "g"), "$&$");
};
const result = backWardInsert("$", 3);
console.log(result);轉載請註明出處，本文鏈接：https://www.uj5u.com/ruanti/462165.html
標籤：javascript 正则表达式 功能 插入