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Java Java Data Structures - Retired Exploring the Java Collection Framework Maps

Getting and error on the return line: /example/Blog.java:44: error: cannot find symbol return catCounts.get(cat);

Why is this error generated? The compiler is not finding variable cat. Is this not the correct way to return each category and count for each category.

com/example/BlogPost.java
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;
  }
}
com/example/Blog.java
package com.example;

import java.util.List;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Set;
import java.util.Map;
import java.util.TreeSet;

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 getCategoryCounts(String catName, Integer catCounter){
    Map <String, Integer> catCounts = new HashMap<String, Integer>();
  for (BlogPost post : mPosts){
    String cat = post.getCategory();
    if(catCounts.get(cat) != null) {
    // Increment the count like before.
      Integer count = catCounts.get(cat);
    count++;
    catCounts.put(cat, count);
    }
else {
    //Start the count out at 1.
    catCounts.put(cat, 1); 
       }
     }
     return catCounts.get(cat);
  }
}    

1 Answer

Craig Dennis
STAFF
Craig Dennis
Treehouse Teacher

Your return statement is outside of your for loop. The variable cat is set inside the for-each loop. It looks to be a scoping problem.

Is your return statement what you actually meant?

Craig Dennis
Craig Dennis
Treehouse Teacher

You might also want to restart the challenge, the method signature seems off too....