hi guys,
Actually to sort elements in the ArrayList i have used Collections.sort(ob);
and Collections.sort(ob,new OwnComparator());
Here in the class OwnComparator i have implemented the interface comparator which contains two methods i.e., compare and equals methods.
If i didn't overrite equals method why its not raising any error.
please suggest your ideas.
import java.util.*;
class sortonarraylist
{
public static void main(
String[] args)
{
ArrayList ob=new ArrayList();
ob.add(10);
ob.add(11);
ob.add(9);
ob.add(5);
System.out.println("Hello World!"+ob);
Collections.sort(ob);
System.out.println("Hello World! sort order"+ob);
Collections.sort(ob,new OwnComparator());
System.out.println("Hello World! our own sort order"+ob);
}
}
import java.util.*;
class OwnComparator implements Comparator
{
public int compare(Object o1,Object o2)
{
return o1.toString().compareTo(o2.toString());
}
/*public boolean equals(Object o){
System.out.println("in equals");
return true;
}*/
};
