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Java Java Data Structures - Retired Getting There Type Casting

Posted by Sanketh Shanbhag
Sanketh Shanbhag
1,560 Points

This in no way is passing, why ?? :( :(

Can you please help me with the answer for type-casting-2. Am just not able to figure it out

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.

    BlogPost objx = (BlogPost) obj;
    System.out.println(objx.getTitle());

    return "";
  }
}

1 Answer

David Lin
David Lin
35,864 Points
David Lin
David Lin
35,864 Points

For Part 1 of challenge, just check if object is of type String, and if so, cast it as such to the result variable:

  public static String getTitleFromObject(Object obj) {
    // Fix this result variable to be the correct string.
    String result = "";
    if (obj instanceof String) {
      result = (String) obj;
    }
    return result;
  }

Then for Part 2, check if object is of type BlogPost, and if so, cast it as such and get its title (which is a string):

  public static String getTitleFromObject(Object obj) {
    // Fix this result variable to be the correct string.
    String result = "";
    if (obj instanceof String) {
      result = (String) obj;
    } else if (obj instanceof BlogPost) {
      result = ((BlogPost) obj).getTitle();
    }
    return result;
  }