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825 Pointscom.example.BlogPost typecasting question on Challenge Task
I got stuck on this last task in the first part of Data Structure course.
This is what I have so far and it's not working.. I couldn't figure out how to return the results of the getTitle method on the newly type-casted BlogPost instance.
I'm also not sure whether the if statement for "if a com.example.BlogPost is passed in for obj that you then cast it to a BlogPost" is right below either..
Please help!
public static String getTitleFromBlogPost(Object obj) { BlogPost result; if (obj instanceof com.example.BlogPost) { result = (BlogPost) obj; return result.getTitle(); } }
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 = obj.toString();
} else {
result = (String) obj;
}
return result;
}
public static String getTitleFromBlogPost(Object obj) {
BlogPost result;
if (obj instanceof com.example.BlogPost) {
result = (BlogPost) obj;
return result.getTitle();
}
}
}
2 Answers
Rob Bridges
Full Stack JavaScript Techdegree Graduate 35,467 PointsHey Jason,
We don't need to create a brand new method to get the title form a blogPost, we can add another if checker to see if it's a blogPost and cast it in there.
Your complete getTitleFromObject method should look like below.
public static String getTitleFromObject(Object obj) {
if (obj instanceof String) {
return (String) obj;
}
else if (obj instanceof BlogPost) {
BlogPost myBlogPost = (BlogPost) obj;
return myBlogPost.getTitle();
}
return "";
}
}
I gave a bit more of a detailed explanation in here
But you were close, just combine it into one method, and you should be set.
Thanks.
Gonzalo Torres del Fierro
Courses Plus Student 16,751 Pointshello Rob, a question, how to solve just task 1....only that
jasongu
825 Pointsjasongu
825 PointsThanks for the answer! I will look at the detailed explanation, it looks very detailed indeed :) Thanks!
Rob Bridges
Full Stack JavaScript Techdegree Graduate 35,467 PointsRob Bridges
Full Stack JavaScript Techdegree Graduate 35,467 PointsGlad I could help!