function vowelsCount(str){
let count = 0;
let vowels = ["a","e","i","o","u"];
for(let letter of str.toLowerCase()){
for(let v of vowels){
if(letter===v){
count++;
}
}
}
return count;
}
const string = "Hello World. I am a developer";
console.log(vowelsCount(string)); // outcome: 10