varargs « Array Object « Java Collection Q&A

1. Var-arg of object arrays vs. object array -- trying to understand a SCJP self test question    stackoverflow.com

I'm having trouble understanding this question, and the explanation of the answer for an SCJP 1.6 self test question. Here is the problem:

class A { }
class B extends A { }
public ...

2. JAVA, array taking a variable number of objects as parameters    stackoverflow.com

I am trying to get an array to take a variable number of objects as input. I am new to programming so I apologize in advance. Here is my code:

public class Rating{
 ...

3. Ternary operator in varargs returning object or array is invalid    stackoverflow.com

This is puzzling me and I would like an explanation.

public foo(EventPoint... eventPoints) { 
  //...
}


boolean isThisHappening;

foo(isThisHappening ? new EventPoint() : new EventPoint[]{});

4. Java varargs allocates array objects?    stackoverflow.com

Wow! I have just realized that varargs methods in Java cause an array to be allocated when they are called. Not sure why I would expect anything different, but should there ...