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Java Java Data Structures - Retired Getting There Type Casting

Jay Bhatt
Jay Bhatt
6,502 Points

How do I account for the type cast to be String & be able to retrieve the title from the BlogPost object?

Please help I have been stuck on this and I am confused. I believe I understand typecasting. However the question wants to check whether obj has a instanceof String. However, if I do that with the if statement then I do not know how to retrieve the title since that is in the BlogPost object.

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

1 Answer

Blake Larson
Blake Larson
13,014 Points

The title of BlogPost is also a String so you can keep the if statement, but add an else statement.

else { result = ((BlogPost) obj).getTitle(); // typecasting obj to a BlogPost instance and calling the getTitle() method to store in the result variable only if obj is not an instanceof String. }

Blake Larson
Blake Larson
13,014 Points

When I say keep the if statement I mean from the first task. You can take the BlogPost another declaration off.