Help!! Don't know how to cast object into BlogPost

Question

Can someone help me? I am confused and don't know how to do this.

com/example/BlogPost.java

package com.example;

import java.util.Date;

public class BlogPost {
    private String mAuthor;
    private String mTitle;
    private String mBody;
    private String mCategory;
    private Date mCreationDate;

    public BlogPost(String author, String title, String body, String category, Date creationDate) {
      mAuthor = author;
      mTitle = title;
      mBody = body;
      mCategory = category;
      mCreationDate = creationDate;
    }

    public String getAuthor() {
      return mAuthor;
    }

    public String getTitle() {
      return mTitle;
    }

    public String getBody() {
      return mBody;
    }

    public String getCategory() {
      return mCategory;
    }

    public Date getCreationDate() {
      return mCreationDate;
    }
}

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 result variable to be the correct string.
    String result = "";
    TypeCastChecker blogPost = (BlogPost) obj;
    if (obj instanceof String) {
      result = (String) obj;
    }
    return result;

  }
}

Answer 1 · 2017-02-25T15:33:13Z

February 25, 2017 3:33pm

BlogPost is a user defined class/object so it would actually be handled in the exact same manner as the String object. Use an if statment to determine if the obj is an instanceof BlogPost and if it passes that test (obj IS a BlogPost) cast the obj to a BlogPost and then call the getTitle instance method of the BlogPost class to store in the String variable result and return result.

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

Welcome to the Treehouse Community

Looking to learn something new?

Matt Song

Matt Song

Help!! Don't know how to cast object into BlogPost

1 Answer

Ted Dunn

Ted Dunn