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Start your free trialXuanzheng Lin
2,466 PointsThe use of equals method in overriding the compareTo
Craig had the code like this
@Override
public int compareTo(Object obj) {
Treet other = (Treet) obj;
if (equals(other)) {
return 0;
}
......
}
I wonder why not the equals method like the name of the object to be compared.equals(other)?
1 Answer
Timothy Hilley
2,292 Pointspublic class Treet implements Comparable {
.... @Override public int compareTo(Object obj) { //method takes in a class and returns an int
Treet other = (Treet) obj; //just placing the target into a variable class inst
if (equals(other)) { //if x.compareTo(y) == 0, return 0;
return 0; //stop this method, they are the same
}
int dateCmp = mCreationDate.compareTo(other.mCreationDate); //otherwise keep going and compare the class' variables
int descriptionCmp = description.compareTo(other.description);
int authorCmp = author.compareTo(other.author);
if (dateCmp == 0) { //if similarities occur, return them
if (descriptionCmp == 0) {
return authorCmp;
}
return descriptionCmp;
}
return dateCmp;
}
}