The parameter passed to the third call to the function foo, assuming the first call is foo("avatar"), is:
NOTE: double quotes are already provided.
public class StringCall {
public static void main(String[] args) {
System.out.println(foo("avatar"));
}
public static int foo(String s) {
if(s.length() < 2) return 0;
char ch = s.charAt(0);
if(ch == 'a' || ch == 'e' || ch == 'i' || ch == 'o' || ch == 'u') return 1 + foo(s.substring(1));
else return foo(s.substring(2));
}
}