Problem: Count vowels in a string. Given "hello world", report 3 vowels (e, o, o). This practices iteration and character checking, two core operations you'll use constantly. Approach: initialize counter to zero, loop through each character, check if vowel (a, e, i, o, u in either case), increment if yes.
After loop, counter holds answer. The check can use multiple comparisons: c == 'a' || c == 'e' || .. Or use find on a vowel string. Convert to lowercase first with tolower(c) for case-insensitive matching.