Objective

Implement a function that converts a single uppercase letter to its lowercase form and returns every other value untouched.

Steps

• If c is an uppercase letter (A to Z), return its lowercase equivalent.
• For any other value, already-lowercase letters, digits, spaces, and symbols, return c unchanged.
• Work on the character codes directly: a lowercase letter sits exactly 32 positions after its uppercase form in ASCII.
• Guard the range first. Blindly adding 32 or OR-ing in 0x20 also mangles non-letters like @ and [, which must pass through as-is.

Objective

Implement a function that converts a single uppercase letter to its lowercase form and returns every other value untouched.

Steps

• If c is an uppercase letter (A to Z), return its lowercase equivalent.
• For any other value, already-lowercase letters, digits, spaces, and symbols, return c unchanged.
• Work on the character codes directly: a lowercase letter sits exactly 32 positions after its uppercase form in ASCII.
• Guard the range first. Blindly adding 32 or OR-ing in 0x20 also mangles non-letters like @ and [, which must pass through as-is.