Question

The toupper() function converts a ______ to the corresponding ______

(a) uppercase, lowercase

(b) lowercase, uppercase

(c) binary, decimal

(d) decimal, binary

I had been asked this question in unit test.

This is a very interesting question from Character Handling in portion String Operations in C of C

Answer 1

Correct choice is (b) lowercase, uppercase

The explanation: The toupper() function is used to convert a lowercase letter to the corresponding uppercase letter.

If the value is a character for which islower() is true and isupper () is true for another set of characters, the toupper() function returns the corresponding character, otherwise, the value is returned unchanged.