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Java Java Data Structures - Retired Getting There Type Casting

Jiten Mistry
Jiten Mistry
4,698 Points
Posted by Jiten Mistry
Jiten Mistry
4,698 Points

Can someone please help me with this question?

I'm not sure what to do here please

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 =  obj;
    return result;
  }
}

1 Answer

Kristian Terziev
Kristian Terziev
28,449 Points

I don't know which step you are stuck at but here are both.

For step one you just have to check if the object in fact a string:

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

For the second task you have to check if the passed object is in fact a BlogPost. If so return it's title:

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

In the end, your code should look something like this:

public static String getTitleFromObject(Object obj) {
  String result = "";

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

  return result;
}