toupper

Your mission

Implement gm_toupper, your own toupper, which returns the uppercase form of a lowercase letter and returns every other character untouched.

See it in action

gm_toupper('a')

Expected result

Your checklist

For your own tracking. Tests grade your code.

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.

More examples

gm_toupper('Z')

Expected result

gm_toupper('5')

Expected result

Constraints

Expected files

toupper.c

Allowed functions

None. Write every helper yourself.

libc

Standard C library

Implements the contract of a function from the standard C library.

toupper

Characters and ASCII

Your mission

Implement gm_toupper, your own toupper, which returns the uppercase form of a lowercase letter and returns every other character untouched.

See it in action

gm_toupper('a')

Expected result

Your checklist

For your own tracking. Tests grade your code.

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.

More examples

gm_toupper('Z')

Expected result

gm_toupper('5')

Expected result

Constraints

Expected files

toupper.c

Allowed functions

None. Write every helper yourself.

libc

Standard C library

Implements the contract of a function from the standard C library.

Tests

Run the tests to grade your code

Build your code, then check each test here. Open a result to inspect its output.

Build

01Lowercase a becomes AWaiting

02Lowercase z becomes ZWaiting

03Lowercase letter in the middleWaiting

04Already uppercase stays unchangedWaiting

05Digit stays unchangedWaiting

06Space stays unchangedWaiting

07Symbol stays unchangedWaiting

08Character just below 'a' stays unchangedWaiting

toupper

Your mission

Implement gm_toupper, your own toupper, which returns the uppercase form of a lowercase letter and returns every other character untouched.

See it in action

gm_toupper('a')

Expected result

Your checklist

For your own tracking. Tests grade your code.

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.

More examples

gm_toupper('Z')

Expected result

gm_toupper('5')

Expected result

Constraints

Expected files

toupper.c

Allowed functions

None. Write every helper yourself.

libc

Standard C library

Implements the contract of a function from the standard C library.

toupper

Characters and ASCII

Your mission

Implement gm_toupper, your own toupper, which returns the uppercase form of a lowercase letter and returns every other character untouched.

See it in action

gm_toupper('a')

Expected result

Your checklist

For your own tracking. Tests grade your code.

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.

More examples

gm_toupper('Z')

Expected result

gm_toupper('5')

Expected result

Constraints

Expected files

toupper.c

Allowed functions

None. Write every helper yourself.

libc

Standard C library

Implements the contract of a function from the standard C library.

Tests

Run the tests to grade your code

Build your code, then check each test here. Open a result to inspect its output.

Build

01Lowercase a becomes AWaiting

02Lowercase z becomes ZWaiting

03Lowercase letter in the middleWaiting

04Already uppercase stays unchangedWaiting

05Digit stays unchangedWaiting

06Space stays unchangedWaiting

07Symbol stays unchangedWaiting

08Character just below 'a' stays unchangedWaiting