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

count = function(a) {
  //var a=document.getElementById("t");
  console.log(a); //to see input string on console
  n = a.length;
  console.log(n); //calculated length of string
  var c = 0;
  for (i = 0; i < n; i++) {
    if ((a[i] == "a") || (a[i] == "e") || (a[i] == "i") || (a[i] == "o") || (a[i] == "u")) {
      console.log(a[i]); //just to verify
      c += 1;
    }
  }

  document.getElementById("p").innerText = c;
}

count of vowels