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Generics question problem

 
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Refer to K&B book Q 16 of Chapter 7-
Given a method declared as:
public static <E extends Number> List<? super E> process(List<E> nums)
A programmer wants to use this method like this:
// INSERT DECLARATIONS HERE
output = process(input);
Which pairs of declarations could be placed at // INSERT DECLARATIONS HERE to allow
the code to compile? (Choose all that apply.)
A. ArrayList<Integer> input = null;
ArrayList<Integer> output = null;
B. ArrayList<Integer> input = null;
List<Integer> output = null;
C. ArrayList<Integer> input = null;
List<Number> output = null;
D. List<Number> input = null;
ArrayList<Integer> output = null;
E. List<Number> input = null;
List<Number> output = null;
F. List<Integer> input = null;
List<Integer> output = null;
G. None of the above.

Here what I understand is that there is a bound on type E , E is anything that extends Number.We pass a List of type E to method process and returns a list of type anything that is superclass of E.

So I did not understand why option C is not correct.
ArrayList<Integer> input = null;
List<Number> output = null;

Here return type is List of type Number where E is Integer and Numberis a superclass of Integer.
 
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Hi neha,

hava a look at the errata
The correct definition for process is:
public static <E extends Number> List<E> process(List<E> nums)
 
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