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Java Java Data Structures - Retired Getting There Type Casting

Eric Shelby
Eric Shelby
28,300 Points

Type Casting problems

I'm having trouble understand this question. "The method getTitleFromObject will be called and passed a String and/or a com.example.BlogPost. For this first task, return the object obj type casted as a String if it is in fact a String." Does it simply want me to somehow add obj to the result variable and return that? Does it want me to use a method from BlogPost.java? I have no idea what I'm doing.

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 = "";
    if (obj instanceof String == true) {
      obj = result;
    }
    return result;
  }
}

2 Answers

You are nearly correct except for your condition and also inside the if statement of the getTitleFromObject method you have not typecast obj as a string and not assign it to result.

This will make result's type a String, which will then be returned as a string as the method requires. Here is my fix:

if(obj instanceof String) { result = (String) obj; }

Keep all other code the same.

if(obj instanceof String) {
    result = (String) obj;
}

Just wanted to add the code formatted.

Eric Shelby
Eric Shelby
28,300 Points

Thanks for your answer. It cleared things up.