Welcome to the Treehouse Community
Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.
Looking to learn something new?
Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.
Start your free trialGabriele Zurla
Courses Plus Student 6,942 PointsI'm getting mad
Got this error:
./com/example/Blog.java:20: error: for-each not applicable to expression type for (String category : post.getCategory()){ ^ required: array or java.lang.Iterable found: String Note: JavaTester.java uses unchecked or unsafe operations. Note: Recompile with -Xlint:unchecked for details. 1 error
Here's my code: Blog.java: http://dpaste.com/0NFNNKW BlogPost.java: http://dpaste.com/29QC13W
package com.example;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
public class BlogPost implements Comparable<BlogPost>, Serializable {
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 int compareTo(BlogPost other) {
if (equals(other)) {
return 0;
}
return mCreationDate.compareTo(other.mCreationDate);
}
public String[] getWords() {
return mBody.split("\\s+");
}
public List<String> getExternalLinks() {
List<String> links = new ArrayList<String>();
for (String word : getWords()) {
if (word.startsWith("http")) {
links.add(word);
}
}
return links;
}
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;
}
}
package com.example;
import java.util.*;
import com.example.BlogPost;
public class Blog {
List<BlogPost> mPosts;
public Blog(List<BlogPost> posts) {
mPosts = posts;
}
public List<BlogPost> getPosts() {
return mPosts;
}
public Map<String, Integer> getCategoryCounts(){
Map<String, Integer> categoryCounts = new HashMap<String, Integer>();
for (BlogPost post: mPosts){
for (String category : post.getCategory()){
Integer count = categoryCounts.get(category);
if(count==null){
count = 0;
}
count++;
categoryCounts.put(category, count);
}
}
return categoryCounts;
}
public Set<String> getAllAuthors() {
Set<String> authors = new TreeSet<>();
for (BlogPost post: mPosts) {
authors.add(post.getAuthor());
}
return authors;
}
}
2 Answers
rtholen
Courses Plus Student 11,859 Points"I am getting mad". Welcome to my world! :)
As defined, a BlogPost can only have one category. It's giving you an error because you are trying to loop over all the categories in a BlogPost with
for (String category : post.getCategory())
The "for loop" is expecting some kind of Collection of categories, but is getting only a single String.
Gabriele Zurla
Courses Plus Student 6,942 PointsThanks, I've done it now!
public Map<String, Integer> getCategoryCounts(){
Map<String, Integer> categoryCounts = new HashMap<>();
for(BlogPost post : mPosts){
String category = post.getCategory();
Integer count = categoryCounts.get(category);
if(count==null){
count=0;
}
count++;
categoryCounts.put(category, count);
}
return categoryCounts;
}
This works.