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AR Aljanabi
Front End Web Development Techdegree Student 10,794 Pointsstuck in Map java
Please can anyone explain to me how we can solve this challenge code??
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;
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> postsCount = new HashMap<String, Integer>();
for (BlogPost post: mPosts){
for(String posts: post.getPosts()){
Integer count = postsCount.get(posts);
if(count == null){
count = 0;
}
count++;
}
}
return postsCount(posts, count);
}
}
1 Answer
Simon Coates
28,694 Points1) you're trying to invoke.getPosts() on a BlogPost object. You want to retrieve the category. As there is only one category for a given object you don't want to use a second for loop.
2) After you update count, you need to put the updated value back ino the postsCount map.
3) I don't know what your trying to accomplish with return postsCount(posts, count);
Take a look at
public Map<String, Integer> getCategoryCounts(){
Map<String, Integer> postsCount = new HashMap<String, Integer>();
for (BlogPost post: mPosts){
String cat = post.getCategory();
Integer count = postsCount.get(cat);
if(count == null){
postsCount.put(cat, 1);
} else {
postsCount.put(cat, count + 1);
}
}
return postsCount;
}
AR Aljanabi
Front End Web Development Techdegree Student 10,794 PointsAR Aljanabi
Front End Web Development Techdegree Student 10,794 PointsThanks man for replying