So I wanna sort an array of Points using the built in sorting method, by a specific coordinate, say x. How can I do this? Heres a sample code:
Point A[] = new Point[10];
// ... Initialize etc.
Arrays.sort(A, x-coordinate);
Is there a built-in comparator for x-coordinates in Point Class? If not, how can I create one and use it. An example would be great.
Thanks.
Point isn't Comparable so you'll need to write your own comparator and pass it in when calling Arrays.sort. Luckily, that's not too hard:
class PointCmp implements Comparator<Point> {
int compare(Point a, Point b) {
return (a.x < b.x) ? -1 : (a.x > b.x) ? 1 : 0;
}
}
Arrays.sort(A, new PointCmp());
Point2D.Double or Point2D.Float then you'll want to do it the way I've updated my answer to.
Double.compare(a.x, b.x). Shorter, and near impossible to get wrong.You can also use Apache Commons Bean Comparator
http://commons.apache.org/beanutils/apidocs/org/apache/commons/beanutils/BeanComparator.html
And then do something like
import org.apache.commons.beanutils.BeanComparator;
Arrays.sort(A, new BeanComparator("x"));
