09 Sept 2026•Go / Python / TypeScript•Easy

To Lower Case

Convert every uppercase English letter in a string to lowercase.

View original LeetCode question

Map each character through its lowercase representation while leaving non-uppercase characters unchanged.

complexity

O(n) time and O(n) output space.

solution files

  • Go to-lower-case/solution.go
  • Python to-lower-case/solution.py
  • TypeScript to-lower-case/solution.ts

Solution files

Go•to-lower-case/solution.go
package main

import "strings"

func toLowerCase(s string) string {
	return strings.ToLower(s)
}
Python•to-lower-case/solution.py
class Solution:
    def toLowerCase(self, s: str) -> str:
        return s.lower()
TypeScript•to-lower-case/solution.ts
function toLowerCase(s: string): string {
  return s.toLowerCase();
}