why wont this work??

Question

import com.example.BlogPost;

public class TypeCastChecker {
  /***************
  I have provided 2 hints for this challenge.
  Change `false` to `true` in one line below, then click the "Check work" button to see the hint.
  NOTE: You must set all the hints to false to complete the exercise.
  ****************/
  public static boolean HINT_1_ENABLED = false;
  public static boolean HINT_2_ENABLED = false;



  public static String getTitleFromObject(Object obj) {
   if (obj instanceof String) {
  return (String) obj;
}
  }
}

I get one error saying that return value is expected but I have clearly put one and checked this against other answered questions of the topic and I cant find what I am doing wrong.

can someone please give me some insight on why this is doing this?

Answer 1 · 2016-01-04T12:22:20Z

January 4, 2016 12:22pm

Hi Dylan,

you are almost there :)

This block proofs whether obj is a String and returns obj casted as a String. Thats correct.

  public static String getTitleFromObject(Object obj) {
   if (obj instanceof String) {
  return (String) obj;
}

But what if obj is a BlogPost. You can use an else statement and after casting obj to BlogPost you can access the getTitle method of the BlogPost and return it. Title is a String so you will get a proper return type ....

You can do it this way:

 if (obj instanceof String) {
      String result = (String) obj;
        return result;
    } else {
      BlogPost bp = (BlogPost) obj;
        return bp.getTitle();
    }

or this way:

 if(obj instanceof String){
      return (String) obj;
    } else {
      return ((BlogPost) obj).getTitle();
    }

Grigorij

Welcome to the Treehouse Community

Looking to learn something new?

Dylan Carter

Dylan Carter

why wont this work??

1 Answer

Grigorij Schleifer

Grigorij Schleifer

Christian Lawrence

Christian Lawrence

Grigorij Schleifer

Grigorij Schleifer