C Source Code/Count the number of vowels in a word

Introduction
Each time you see a vowel, add one. For example:

because.

b (no) e (+1=1) c (no) a (+1=2) u (+1=3) s (no) e (+1=4)

One way of doing this is to scan the string "because" from left to right. We read in a character, and check if it is a vowel. The character is compared to a dictionary of vowels. This "dictionary" is stored in the line static const char vowels[] = "aeiouAEIOU";

so in this code, the lowercase and uppercase letters are all vowels.