Counting number of vowels in a string with JavaScript

Question

I\'m using basic JavaScript to count the number of vowels in a string. The below code works but I would like to have it cleaned up a bit. Would using .includes()

Answer 1

You can convert the given string into an array using the spread operator, and then you can filter() the characters to only those which are vowels (case-insensitive).

Afterwards, you can check the length of the array to obtain the total number of vowels in the string:

const vowel_count = string => [...string].filter(c => 'aeiou'.includes(c.toLowerCase())).length;

console.log(vowel_count('aaaa'));            // 4
console.log(vowel_count('AAAA'));            // 4
console.log(vowel_count('foo BAR baz QUX')); // 5
console.log(vowel_count('Hello, world!'));   // 3