Challenge: Count Vowels 🔢

Why this matters: text analysis, search ranking, and even simple spell‑check tools rely on being able to inspect and classify characters efficiently.

Count how many vowels (a, e, i, o, u) are in a string.

Examples

countVowels("hello");      // 2
countVowels("JavaScript"); // 3
countVowels("xyz");        // 0

Approaches

Method 1: Loop through characters

const vowels = "aeiou";
let count = 0;
for (let char of str.toLowerCase()) {
  if (vowels.includes(char)) {
    count++;
  }
}

Method 2: Filter

str.split("").filter(c => "aeiou".includes(c.toLowerCase())).length

Method 3: Match with regex

(str.match(/[aeiou]/gi) || []).length

Your Turn!

Count the vowels.