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Start your free trialParamvir Singh
1,517 Pointsfor-each loop cannot be used here
I was using a nested for-each loop for Maps. Then I was using for-each loop for the String type but it said it cannot be done.
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.List;
import java.util.Set;
import java.util.TreeSet;
import java.util.Map;
import java.util.HashMap;
import com.example.BlogPost;
import java.util.*;
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> map = new HashMap<String, Integer>();
for ( BlogPost x : mPosts ) {
for ( String y : x.getCategory() ) {
Integer count = map.get(y);
if ( count == null ) {
count = 0;
}
count++;
map.put(y, count);
}
}
return map;
}
public Set<String> getAllAuthors() {
Set<String> authors = new TreeSet<>();
for (BlogPost post: mPosts) {
authors.add(post.getAuthor());
}
return authors;
}
}
2 Answers
andren
28,558 PointsThe getCategory
method returns a single String
, not a list of strings. A String
by itself is not iterable in Java.
A BlogPost
can only have one category assigned to it, so no looping is required when it comes to categories. Just use the String
getCategory
returns directly like this:
public Map<String, Integer> getCategoryCounts () {
Map<String, Integer> map = new HashMap<String, Integer>();
for ( BlogPost x : mPosts ) {
String y = x.getCategory(); // Assign the category to y
Integer count = map.get(y);
if ( count == null ) {
count = 0;
}
count++;
map.put(y, count);
}
return map;
}
And then your code will work.
Paramvir Singh
1,517 Pointsoohhhh, that makes so much sense and I feel like a stupid.
Thanks a lot for your help,andren.