Java
import java.util.Scanner;
public class Main {
private static boolean isVowel(char c) {
c = Character.toLowerCase(c);
return c == 'a' || c == 'e' || c == 'i' || c == 'o' || c == 'u';
}
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
System.out.print("Enter a string: ");
String s = sc.nextLine();
int count = 0;
for (int i = 0; i < s.length(); i++) {
if (isVowel(s.charAt(i))) {
count++;
}
}
System.out.println("Vowels: " + count);
sc.close();
}
}Output
Enter a string: hello world Vowels: 3
We scan each character and increment count when it is a vowel.