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Start your free trialSean Flanagan
33,235 PointsTypecasting Challenge Task 2
Hi. I'm stuck on this one.
Here's my code:
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 = true;
public static String getTitleFromObject(Object obj) {
// Fix this result variable to be the correct string.
if (obj instanceof com.example.BlogPost) {
return (getTitle) result;
}
if (obj instanceof BlogPost) {
BlogPost post = (BlogPost) obj;
return result = (String) post.getTitle();
}
return result;
}
}
I'd be grateful for any help. :-)
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 = true;
public static String getTitleFromObject(Object obj) {
// Fix this result variable to be the correct string.
if (obj instanceof com.example.BlogPost) {
return (getTitle) result;
}
if (obj instanceof BlogPost) {
BlogPost post = (BlogPost) obj;
return result = (String) post.getTitle();
}
return result;
}
}
2 Answers
Jon Kussmann
Courses Plus Student 7,254 PointsHi Sean,
What sort of error are you getting? I personally solved part two like so:
if (obj instanceof BlogPost) {
return ((BlogPost)obj).getTitle();
}
If you want it spread out a little more:
if (obj instanceof BlogPost) {
BlogPost post = (BlogPost)obj;
return post.getTitle();
}
Rob B
11,677 PointsThanks for the help. I've had to check everything in this course since the beginning because the instructions have always been missing something, or has been too vague on something.
Thanks again for the help.
Sean Flanagan
33,235 PointsSean Flanagan
33,235 PointsHi Jon. Your code was a big help. Thanks again. :-)
Rulon Taylor
2,762 PointsRulon Taylor
2,762 PointsHi Jon,
Your comment was exactly the help I needed. Can you explain the syntax behind ((BlogPost)).getTitle();?
I tried BlogPost obj.getTitle() and got a compiler error because it thought I was casting the result of getTitle as BlogPost. How did you know adding the parenthesis would work and was required?
Thanks!
Aditya Puri
1,080 PointsAditya Puri
1,080 PointsJon 2 questions-
1) Why do we have 2 extra () around the line
(BlogPost)obj
? Can't we just do return((BlogPost)obj).getTitle();
2) When do we use these type conversions?