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Java Java Data Structures Getting There Type Casting

ambareesh M
ambareesh M
6,122 Points

The method getTitleFromObject will be called and passed a String and/or a com.example.BlogPost. For this first task, ret

No idea

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 = "";
    return result;
  }
}

1 Answer

calp
calp
10,317 Points

You need to check if the object that is passed in is an instance of a string or a blogpost and return a string result accordingly. If the object is an instance of a string then you just need to cast the object to the result variable so that it is returned. If the object is an instance of a blogpost then you need to set the result variable to the blogposts title so that is returned.

  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) {
      BlogPost bp = (BlogPost) obj;
      result = bp.getTitle();
    }
    return result;
  }

`