Compiler problems in Java Data Structures (SETS), and I don't know why, please help!

Question

So when I try to compile this I get these errors ./com/example/Blog.java:21: error: class, interface, or enum expected public Set getAllAuthor(){ ^ ./com/example/Blog.java:23: error: class, interface, or enum expected for(BlogPost author : mposts){ ^ ./com/example/Blog.java:25: error: class, interface, or enum expected } ^ ./com/example/Blog.java:27: error: class, interface, or enum expected } ^ Note: JavaTester.java uses unchecked or unsafe operations. Note: Recompile with -Xlint:unchecked for details. 4 error

I thought I had imported all the proper things and I'm out of ideas on how to fix it any advice would be helpful please and thank you!

com/example/BlogPost.java

package com.example;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import java.util.Set;
import java.util.TreeSet;



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.Set;
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> getAllAuthor(){
  Set<String> allAuthors = new TreeSet<String>();
  for(BlogPost author : mposts){
    allAuthors.add(post.getAuthor());
  }
  return allAuthors;    
}

Answer 1 · 2018-04-04T03:06:02Z

April 4, 2018 3:06am

Hi Winston

There are some revisions need to be done in your code. You almost made it but there some typos that will matter in the test challenge. As you already import both java.util.Set and java.util.TreeSet the revisions only occur in the getAllAuthors method. This is the revision in your original code:

public Set<String> getAllAuthor(){//<--This is should be getAllAuthors! The lack of s as in plural will matters in the test to determine you pass the challenge or not
  Set<String> allAuthors = new TreeSet<String>();
  //this is wrong: for(BlogPost author : mposts){<--you should put BlogPost post as you use post.getAuthor inside the for
//loop, and also it is mPost not mpost! this is how you should code it:
   for(BlogPost post : mPost){
    allAuthors.add(post.getAuthor());
  }
  return allAuthors;    
}

I hope these revisions can help a little. Happy coding and good luck.

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Winston Grant

Winston Grant

Compiler problems in Java Data Structures (SETS), and I don't know why, please help!

1 Answer

Yanuar Prakoso

Yanuar Prakoso

Winston Grant

Winston Grant