Write a JavaScript program to count the number of vowels in a given string.
<html>
<head>
<title>Count vowels in a string</title>
</head>
<body>
<script>
var str = prompt('Enter the string', '')
var vowels = countVowels(str)
document.write("Given string: " + str)
document.write("<br>Number of Vowels: " + vowels)
function countVowels(s)
{
var i=0, count=0
var ch
for(var i=0; i<s.length; i++)
{
ch = s.charAt(i)
if(ch == 'a' || ch == 'A' || ch == 'e' || ch == 'E' || ch == 'i' ||
ch == 'I' || ch == 'o' || ch == 'O' || ch == 'u' || ch == 'U')
{
count++
}
}
return count;
}
</script>
</body>
</html>
