Return the number of English vowels in a null-terminated string. Count upper- and lower-case letters, and treat a null pointer as an empty string.
SovranCode4Write down the input contract and the failure cases before coding.
Use your C runtime locally, then compare with solution.c.
A C string has no length stored beside it; its contract is the terminating null character. A read-only cursor makes that contract visible and keeps the caller's buffer unchanged. The switch handles both cases without locale-dependent surprises.
your-solution.c.solution.c only after a real attempt.This beginner C exercise focuses on C string traversal, Character comparisons, Null termination. Its requirements define the exact behavior to implement before you write code.
Start with the displayed example input and expected output, then test a boundary case suggested by the requirements. Write and compile the starter in your local C environment, exercise the example and edge cases, then compare your approach with solution.c.
Attempt Count vowels in a C string first. Then open the read-only solution file to compare the contract, edge-case handling, and implementation choices—not simply to copy the final code.