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Start your free trialTimmie Nilsson
4,463 PointsA question about equals
Hi in this if I make a equals(other)
But I don't understad what the equals compare 'other' to?
Usually I see 'example.equals(hamster)' I googles it but all example shows the same as mine... How does this works?
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 other = (BlogPost) obj;
if(equals(other)){
return 0;
}
return 1;
}
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;
}
}
1 Answer
Steve Hunter
57,712 PointsHi Timmie,
The compareTo
method is comparing the instance of BlogPost
that compareTo
is being called on, to the argument passed in.
So, to use compareTo
, you need to create an instance of BlogPost
first. It is that instance which is compared to the obj
.
You can make this clearer by using the this
keyword to indicate you are using the instance of the class:
public int compareTo(Object obj){
if(this.equals((BlogPost) obj)){
return 0;
}
return 1;
}
Make sense?
Steve.
Timmie Nilsson
4,463 PointsTimmie Nilsson
4,463 PointsWell it makes sense but a little confusion :)