Objective

Implement a function that returns the uppercase form of a lowercase letter and returns every other character untouched.

Steps

• If c is a lowercase letter (between a and z), return its uppercase counterpart.
• For anything else, letters that are already uppercase, digits, spaces, punctuation, return c exactly as it was given.
• Letters live next to each other in the ASCII table, so the gap between a lowercase letter and its uppercase form is the same constant for every letter; derive the shift from character literals instead of hardcoding a magic number.
• Watch the boundaries: only a through z should change. The character just below a must pass straight through.

Objective

Implement a function that returns the uppercase form of a lowercase letter and returns every other character untouched.

Steps

• If c is a lowercase letter (between a and z), return its uppercase counterpart.
• For anything else, letters that are already uppercase, digits, spaces, punctuation, return c exactly as it was given.
• Letters live next to each other in the ASCII table, so the gap between a lowercase letter and its uppercase form is the same constant for every letter; derive the shift from character literals instead of hardcoding a magic number.
• Watch the boundaries: only a through z should change. The character just below a must pass straight through.