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Java Java Data Structures - Retired Getting There Type Casting

michael figueroa
michael figueroa
5,680 Points
Posted by michael figueroa
michael figueroa
5,680 Points

if the blog post class is imported why then is the getTitle() method not being found.

if the class is being imported and the object obj is type cast as a BlogPost. why then is the method getTitle() not being found during compile time. The question even asks me to use the method after obj is type cast as a BlogPost. is there something wrong with my code?

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){
      result = (String)obj;
    }else if(obj instanceof com.example.BlogPost){
      result = (BlogPost)obj.getTitle();
    }
    return result;
  }
}

1 Answer

Eric Stermer
Eric Stermer
9,499 Points
Eric Stermer
Eric Stermer
9,499 Points 
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){ //<--- not related but dont need com.example here
      // result = (BlogPost)obj.getTitle(); <--- you have to set the casted object first to a variable of the type BlogPost
      // Like this
      BlogPost post = (BlogPost) obj;
      result = post.getTitle();
      // I am not totally sure why but this should fix it
    }
    return result;
  }