Interface name as a Type
- by user1889148
I am trying to understand interfaces in Java and have this task to do which I am a stack with. It must be something easy, but I don't seem to see the solution. Interface contains a few methods, one of them should return true if all elements of this set are also in the set. I.e.
public interface ISet{
//some methods
boolean isSubsetOf(ISet x);
}
Then the class:
public class myClass implements ISet{
ArrayList<Integer> mySet;
public myClass{
mySet = new ArrayList<Integer>();
}
//some methods
public boolean isSubsetOf(ISet x){
//method body
}
}
What do I need to write in method body? How do I check that the instance of myClass is a subset of ISet collection? I was trying to cast, but it gives an error:
ArrayList<Integer> param = (ArrayList<Integer>)x;
return param.containsAll(mySet);
