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Start your free trialmayur lalwani
992 Pointsunable to solve code.where's the error?
The code is perfectly written according to me but I cannot find an error
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 String[] getWords() {
return mBody.split("\\s+");
}
public String getAuthor() {
return mAuthor;
}
public String getTitle() {
return mTitle;
}
@Override
public int compareTo(Object obj){
BlogPost other = (BlogPost)obj;
if(equals(other)){
return 0;
}
int dateCmp = mCreationDate.compareTo(other.mCreationDate);
if(dateCmp == 0){
return mDescription.comareTo(other.mDescription);
}
return dateCmp;
}
public String getBody() {
return mBody;
}
public String getCategory() {
return mCategory;
}
public Date getCreationDate() {
return mCreationDate;
}
}
1 Answer
Steve Hunter
57,712 PointsHi Mayur,
You're very close! (And you have a typo in your second compareTo()
method)
Try this:
public int compareTo(Object obj){
BlogPost bp = (BlogPost) obj;
if(bp.equals(this)){
return 0;
}
if(this.mCreationDate.before(bp.mCreationDate)){
return -1;
}
return 1;
}
We cast obj
to a BlogPost
called bp
. If bp
is equal to the current instance, this
, return zero. Else decide which comes first, using the before
method comparing the mCreationDate
of both the bp
instance and this
instance. If they're equal, we return zero and if one is before the other we return 1 or -1 depending on which order they fall in.
I hope that helps.
Steve.
Steve Hunter
57,712 PointsSteve Hunter
57,712 PointsWe could use parts of your code to do the same.
If we remove the
if
statement that looks for equality and comparesmDescription
- we've done the equals bit already. Then, if we use yourother
BlogPost
instance that you've created you get this:That should work. This uses the
compareTo()
method, rather than thebefore()
method, which is fine. It takes fewer lines of code but adds nothing to the clarity of the output - it isn't user-friendly. You can also return the comparison directly;dateCmp
isn't doing anything.Steve.
mayur lalwani
992 Pointsmayur lalwani
992 PointsThanks a lot..