Counting unique characters in a String given by the user

Question

I have to write a program that counts the uniques characters in a String given by the user. For example \"abc\" returns 3 and \"aabbccd\" returns 4. I am not allow to use advan

Answer 1

String myString = "";

for(int i=0; i< word.length(); i++) {
    if(myString.indexOf(word.charAt(i)) == -1) {
        System.out.println(word.charAt(i));
        myString = myString + word.charAt(i);
    }
}
return myString.length();