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Java Java Data Structures Getting There Type Casting

Posted by Abhilasha jangid
Abhilasha jangid
2,925 Points

how to add type casting

where I define Object & how I passed the value

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;
  }
}

2 Answers

Anders Björkland
Anders Björkland
7,481 Points
Anders Björkland
Anders Björkland
7,481 Points

Hi Abhilasha,

In this challenge you are asked to do the type cast in the class TypeCastChecker, in its method getTitleFromObject. The object that is passed to the method could be passed from wherever, but imagine there is a Main class that has a main-method that is simply not included for reference in this challenge. It could look like this: 

public class Main {
    public static void main(String[] args) {
        String passThisObject = "this is a String that is passed as an Object to TypeCastChecker.getTitleFromObject()"

        // The String object can be passed to the method since it is a subclass to the class Object. The method  
        // receives an Object and has to check that it is of a certain type with the instanceof keyword, it recognizes  
        // the object as a String, casts the Object to a String and returns the result to our variable result.
        String result = TypeCastChecker.getTitleFromObject(passThisObject);
    }
}

The logic for checking the type of the object is done in the class TypeCastChecker, which can't be seen from the class Main, just as the class TypeCastChecker won't know what type of objects are being passed to its method.

I hope this will get you on the right track. If you have any more questions, just ask. Good luck!

Abhilasha jangid
Abhilasha jangid
2,925 Points
Abhilasha jangid
Abhilasha jangid
2,925 Points

THANK you for your help