First Repeated Character in String | Dataford Interview Questions

How do you find the first repeated character in a string?

Implement first_repeated_character(s). Treat uppercase and lowercase English letters as the same character, and return the repeated character in lowercase. Return None when no character repeats.

Constraints

0 <= len(s) <= 10^5
s contains only uppercase and lowercase English letters
Character comparison is case-insensitive
Return the repeated character in lowercase, or None if no character repeats

Function Signature

def first_repeated_character(s):

Your question is First Repeated Character in String. Start with the requirements in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.

Problem

How do you find the first repeated character in a string?

Implement first_repeated_character(s). Treat uppercase and lowercase English letters as the same character, and return the repeated character in lowercase. Return None when no character repeats.

Constraints

0 <= len(s) <= 10^5
s contains only uppercase and lowercase English letters
Character comparison is case-insensitive
Return the repeated character in lowercase, or None if no character repeats

Function Signature

def first_repeated_character(s):

Your question is First Repeated Character in String. Start with the requirements in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.