Are all the letters in the input string capital letters?
Examples:
'MNOP' -> 1 'MN0P' -> 0
Make your checks robust to brute force approach.
You should add more checks to the test suite.
I agree with Oleg and Gaik: please have a rich test suite.
You should include a test case with a string that contains lowercase letters as well as uppercase letters, numbers, and symbols.
It is not checking lowercase letters. Give some test for that.Otherwise problem statement should be different.
I added a test for lowercase.
the description of the problem is misspecified. "Are all the letters in the input string capital letters?" Numbers are not letters. The tests treat numbers as lower case.
Test cases are not according to problem statement.