Join the string with same separator used to split

Question

I have a string that need to be split with a regular expression for applying some modifications.

eg:

const str = \"Hello+Beautiful#World\";
const spl         


        

Answer 1

You could get the missing substrings by iterating the splitted value and check the parts.

var string = "Hello++#+Beautiful#World",
    splitted = string.split(/[\+#]+/),
    start = 0,
    symbols = splitted.map((s, i, { [i + 1]: next }) => {
        var index = string.indexOf(next, start += s.length);
        if (index !== -1) {
            var sub = string.slice(start, index);
            start = index;
            return sub;
        }
        return '';
    });

console.log(symbols);
console.log(splitted.map((s, i) => s + symbols[i]).join(''));