Code returns undefined instead of return value

Question

I have string 101000 or 1010100 in which I am trying to replace 100 recursively using function remove data. The function removedata should return "yes" when string is empty and "no" when string is not empty while replacing it with value 100.

It works fine for string 1010100. It returns "no" but not for string 101000 where it becomes empty.

console.log(removedata("1010100"));
console.log(removedata("101000"));

function removedata(data) {
  data = data.replace("100", "");
  if (data.length == 0) {
    return "yes";
  } else {
    if (data.indexOf("100") > -1 && data.length > 0) {
      removedata(data);
    } else {
      return "no";
    }
  }
}

when 1010100 it returns no but when 101000 it returns undefined

so you want to remove all occurrences of '100' like: 100a100b1001c should become ab1c ? — Andu Andrici
– Andu Andrici, Commented Apr 21, 2019 at 20:49
wouldn't regex greatly simplify this? data = data.replace(/100/g, ""); — Andu Andrici
– Andu Andrici, Commented Apr 21, 2019 at 20:55

Jack Bashford · Accepted Answer · 2019-04-21 20:50:45Z

3

You need to return the recursive call:

console.log(removedata("1010100"));
console.log(removedata("101000"));

function removedata(data) {
  data = data.replace("100", "");
  if (data.length == 0) {
    return "yes";
  } else {
    if (data.indexOf("100") > -1 && data.length > 0) {
      return removedata(data);
    } else {
      return "no";
    }
  }
}

Now it returns yes for the second one because all of the 100s have been removed and the string is empty.

answered Apr 21, 2019 at 20:50

Jack Bashford

44.3k11 gold badges56 silver badges84 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Code-Apprentice · Accepted Answer · 2019-04-21 20:51:08Z

0

function removedata(data) {
  data = data.replace("100", "");
  if (data.length == 0) {
    return "yes";
  } else {
    if (data.indexOf("100") > -1 && data.length > 0) {
      removedata(data);                                     // This branch does not return anything
    } else {
      return "no";
    }
  }
}

answered Apr 21, 2019 at 20:51

Code-Apprentice

84k26 gold badges162 silver badges289 bronze badges

Collectives™ on Stack Overflow

Code returns undefined instead of return value

2 Answers 2

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related