Why Does Java Skip My If Statement in a While Loop?

I'm trying to construct a program that counts the amount of vowels in a given string. Everything seems to run fine until I get to the while loop. It completely skips my if statement and goes straight to the incrementation of integer r. I feel that this is a syntax error; however, I can't imagine what it could be. Any thoughts?

String e [ ] = {"a", "e", "i", "o", "u",};
        String a = "banana";
        int r = 0;
        int b = 0;
        int c = 1;
        int z = 0;
        String q = " ";
        for(int i = 0; i < a.length(); i++){
            q = a.substring(b, c);
            b++;
            c++;
            while(r < e.length - 1){
                if(q.equalsIgnoreCase(e [r])){
                    z = z + 1;

                }
                r++;
            }

        }
        System.out.println(z);
    }
        }