Using recursion to return first duplicate of a string. I can print but not return the answer and am not sure why

Asked Jun 15 '20 at 00:15

Active Aug 12 '22 at 23:45

Viewed 16 times

I am trying to return the first letter that is a duplicate within a string. I am able to do it with the print method but always get none if I try to return the string.

This code works:

def recurringLetter(word):
    if word[0] == word[1]:
        print(word[0])
    elif len(word) == 0:
        print("None")
    else:
        recurringLetter(word[1:])

string = input()
recurringLetter(string)

But this code always returns none:

def recurringLetter(word):
    if word[0] == word[1]:
        return word[0]
    elif len(word) == 0:
        return None
    else:
        recurringLetter(word[1:])

string = input()
recurringLetter(string)

edited Jun 15 '20 at 00:15

Nick

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asked Jun 15 '20 at 00:15

Unknown Unknowns

4

You have to `return` the result of the recursion i.e. `return recurringLetter(word[1:])` – Nick Jun 15 '20 at 00:16
Thank you Nick, that indeed did the trick. Thanks for the edit too, I made a real mess of my first post. It looks a lot better now. – Unknown Unknowns Jun 15 '20 at 00:21
No worries. You just got the formatting character wrong, it should be three backticks ```, not three single quotes ''' – Nick Jun 15 '20 at 00:22
Yeah was changing it and it said you already had. lol. Your so quick and helpful thanks. – Unknown Unknowns Jun 15 '20 at 00:24

Using recursion to return first duplicate of a string. I can print but not return the answer and am not sure why

0 Answers0