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Java Java Data Structures Getting There Type Casting

abhi reddy
abhi reddy
1,636 Points

I didnt get it

what exactly is the task

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 = "";
  System.out.println( obj instanceof Object);
    return obj.toString();
  }

}

1 Answer

andren
andren
28,558 Points

The task is to:

  1. Check if the object passed in is a string (using an if statement with instanceof)

  2. Set result to the object cast as a string

  3. Then return result

How to cast objects was demonstrated in the Type Casting video that preceded this challenge. I would recommend you rewatch the video if you are still unclear on how to do casting, but as a mini summary you place parentheses enclosing the thing you want to cast into in front of the object you want to cast.

So if I wanted to cast a variable called example into a string it would look like this:

String stringVariable = (String) example;
// stringVariable would now equal example cast as a String.