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Start your free trialCHIRAG SARAOGI
1,280 PointsError at getCategory function call inside the for loop.
I hope this logic is correct. I am getting one error at getCategory() function call. Please help me understand where am I going wrong.
Thanks a lot
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.Map;
import java.util.Set;
import java.util.TreeSet;
import java.util.HashMap;
import java.lang.Iterable;
import com.example.BlogPost;
public class Blog {
List<BlogPost> mPosts;
public Blog(List<BlogPost> posts) {
mPosts = posts;
}
public List<BlogPost> getPosts() {
return mPosts;
}
public Set<String> getAllAuthors() {
Set<String> authors = new TreeSet<>();
for (BlogPost post: mPosts) {
authors.add(post.getAuthor());
}
return authors;
}
public Map<String, Integer> getCategoryCounts()
{
Map<String, Integer> result= new HashMap<String, Integer>();
for( BlogPost catPost : mPosts)
{
for ( String hashTag : catPost.getCategory())
{
Integer count = result.get(hashTag);
if (count == null)
{
count = 0;
}
count++;
result.put(hashTag, count);
}
}
return result;
}
}
2 Answers
Dan Johnson
40,533 PointsgetCategory returns a String
so there's nothing to iterate through. Instead of the inner for-in loop you can switch to assignment:
String hashTag = catPost.getCategory();
CHIRAG SARAOGI
1,280 Pointspublic Map<String, Integer> getCategoryCounts() { Map<String, Integer> result= new HashMap<String, Integer>(); for( BlogPost catPost : mPosts) { String hashTag = catPost.getCategory(); } return result; }
Dan Johnson
40,533 PointsThe logic inside the inner loop was fine, just the inner loop itself was unneeded. As an outline:
// For each blog post
for( BlogPost catPost : mPosts)
{
// Get the category
String hashTag = catPost.getCategory();
// Use the category as a key
Integer count = result.get(hashTag);
if (count == null)
{
count = 0;
}
count++;
result.put(hashTag, count);
}
CHIRAG SARAOGI
1,280 PointsCHIRAG SARAOGI
1,280 PointsI deleted the inner for loop and inserted the above code, got multiple errors. Please help me understand the code.
Thank you Chirag Saraogi
Dan Johnson
40,533 PointsDan Johnson
40,533 PointsIf you can post your updated code I'll look over it again.