Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

Java Java Data Structures - Retired Getting There Type Casting

Sean Flanagan
Sean Flanagan
33,235 Points

Typecasting Challenge Task 1

Hi.

I've no idea how to do this. Can anyone help please?

Thanks.

Sean

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 = "";
    return result;
  }
}

2 Answers

Jon Kussmann
PLUS
Jon Kussmann
Courses Plus Student 7,254 Points

Hi Sean,

This is how I solved it. I first checked if 'obj' was a String using the instanceof keyword in Java. If it was the case, I returned the obj cast as a String like so:

if (obj instanceof String) {
  return (String) obj;
}

I hope this helps, if not please let me know.

Sean Flanagan
Sean Flanagan
33,235 Points

Hi Jon.

I pasted your code right below the comment line and it worked. Thank you. :-)

Michael Macdonald
Michael Macdonald
34,265 Points

Hi,

Thanks, I used this code as well, but I don't understand what:

String result = ""; return result;

does at the end of the method.. Is there because we need to return something...?