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Java Java Data Structures - Retired Organizing Data Comparable

Posted by Matthew Earlywine
Matthew Earlywine
2,560 Points

Struggling on Task 2

In this step, cast the Object passed to the compareTo method to a com.example.BlogPost. Check for equality first, if they are equal return 0. Leave the default return of 1 in place for this step.

Not sure what to really do here. I thought I would follow along with my workspace but I am not sure what I am doing wrong.

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

import java.util.Date;

public class BlogPost implements Comparable {
  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(Object obj) {
    BlogPost blogpost = (BlogPost) obj;
    if (equals(other)) {
    return 0;
    }
  }

  public String[] getWords() {
    return mBody.split("\\s+");
  }

  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;
  }
}

3 Answers

jcorum
jcorum
71,830 Points

Your parameter for the compareTo() function is obj, but you say if (equals(other)) { . . .` Here's the finished function:

  public int compareTo(Object obj) {
    BlogPost blogpost = (BlogPost) obj;
    if (equals(obj)) {
      return 0;
    } else {
      return mCreationDate.compareTo(blogpost.mCreationDate);
    }
  }
steve kevin arias serrano
steve kevin arias serrano
9,037 Points

this is the same tha you code but i don't understand why you us obj instead blogpost BlogPost blogpost = (BlogPost) obj; if(equals(blogpost)) { return 0; } return mCreationDate.compareTo(blogpost.mCreationDate);

Bianca Christian
Bianca Christian
3,524 Points

why are you comparing the creation date

Matthew Earlywine
Matthew Earlywine
2,560 Points
Matthew Earlywine
Matthew Earlywine
2,560 Points

Thanks!

Imran Asif
Imran Asif
7,514 Points
Imran Asif
Imran Asif
7,514 Points

public int compareTo(Object obj){ BlogPost bp= (BlogPost)obj; if(equals(bp)){ return 0; }

return 1;