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Start your free trialOmar Amin
Courses Plus Student 1,194 PointsDon't understand what is asked
Hi guys, I am doing the second task in the "Type Casting" exercise in the Java Data Structures course and I can't really understand what is being asked. This is the question:
"Now make sure that if a com.example.BlogPost is passed in for obj that you then cast it to a BlogPost. Return the results of the getTitle method on the newly type-casted BlogPost instance.
I've included BlogPost.java for your reference only." Isn't com.example.BlogPost the way to address the class when importing? If so then how it can be passed as a parameter for a method? It's confusing a little bit.
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;
}
}
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;
}
return result;
}
}
1 Answer
Joshua O'Brian
20,747 PointsYou need to see if the object is an instance of BlogPost then you need to cast it to a BlogPost and then get the Title. This way it is returning the proper String
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;
}
if(obj instanceof BlogPost){
BlogPost post = (BlogPost) obj;
result = post.getTitle();
}
return result;
}
}
Omar Amin
Courses Plus Student 1,194 PointsOmar Amin
Courses Plus Student 1,194 PointsYeah thanks it worked.