How to swap two adjacent characters in a string variable in Javascript

Question

let string = 'abcdefghij'; the result I want string = 'abdcefhgij'. The changes should be made are cd to dc and gh to hg rest of the string is unaltered.

Does this answer your question? [Javascript swap characters in string](https://stackoverflow.com/questions/48571430/javascript-swap-characters-in-string) — Ivica Pesovski, Apr 02 '21 at 09:20

score 0 · Answer 1 · answered Apr 03 '21 at 01:43

    const string1 = 'abcdefghij'.replace(/[cd]/g, (c) => (c == 'c' ? 'd' : 'c'));
    console.log(string1);
    const string2 = string1.replace(/[gh]/g, (c) => (c == 'g' ? 'h' : 'g'));
    console.log(string2);

I did this. finally got the result in the form of string2. Anyone could suggest how to do it in one go?

score 0 · Accepted Answer · answered Apr 04 '21 at 12:27

To do it in one go, create a function that will map each characters you want to swap, like this:

function charReplace(char) {
    if(char == 'c') return 'd';
    if(char == 'd') return 'c';
    if(char == 'g') return 'h';
    if(char == 'h') return 'g';
}

Then you can pass this function as the second parameter to the replace function like this:

const originalString = 'abcdefghij';
const replacedString = originalString.replace(/[cdgh]/g, ($1) => charReplace($1));

If you need to map more chars, just add if blocks in the charReplace function. If it gets too long, you can implement it by keeping the map into an array and returning the element at the correct index.

Thank you so much Mr. Ivica !! You made it simpler !! – PVD Apr 05 '21 at 02:31 — PVD, Apr 05 '21 at 02:31
@PVD mark the answer as accepted please if it helped you. – Ivica Pesovski Apr 05 '21 at 07:20 — Ivica Pesovski, Apr 05 '21 at 07:20

How to swap two adjacent characters in a string variable in Javascript

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