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Java Java Data Structures - Retired Getting There Type Casting

Anthony Lau
Anthony Lau
1,898 Points
Posted by Anthony Lau
Anthony Lau
1,898 Points

don't know how to pass it

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

I think it is right, but it always occur error

TypeCastChecker.java 
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) {
    // Fix this return statement to be the correct string.
    if (obj instanceof String){
      return (String)obj;
    }
    if(obj instanceof BlogPost){
      return (String) obj.getTitle();
    }
  }
}

2 Answers

Craig Dennis
STAFF
Craig Dennis
Treehouse Teacher
Craig Dennis
Craig Dennis
Treehouse Teacher

Hmmm...you know that it is a BlogPost, but then you cast it to a String. You are super super close.

Let me know if that hint helps. I'll give you another if it doesn't.

Yongshuo Wang
Yongshuo Wang
5,500 Points
Yongshuo Wang
Yongshuo Wang
5,500 Points

Hi, I follow your code, there are some compile error with it. Please see the code below.

public class TypeCastChecker{
  public static void main(String[] args){
    BlogPost post = new BlogPost("blog title");

    System.out.println("First title is " + getTitleFromObject(post));
    System.out.println("Second title is " + getTitleFromObject("Second"));

  }

  private static String getTitleFromObject(Object obj){
    String returnTitle = "";

    if (obj instanceof String)
      returnTitle =  (String) obj;

    if (obj instanceof BlogPost)
      returnTitle =  ((BlogPost)obj).getTitle();

    return returnTitle;
  }
}