Subclasses and classes

Question

Hey there guys. I'm new to the forums, and hope to contribute to the community in the future.
I start here with a question. I'm new to programming in Java, and have been studying it on one of the subjects on my course. I recently had a doubt which I tried asking about, but I got no conclusive answer from anyone. The problem is the following:
There's this program where I need to create a array (I don't know if array is the right word, as from what I've sensed the definitions between C and Java terminology vary a bit) of a number, N, objects of a class, which has subclasses. Imagine a footall team, the class team which has said array of players, Player being said class with the subclasses being the kind of players (Goalkeeper, etc etc). Imagine the number of players is 20, for example, from which 10 are of the subclass A, and 10 are of the subclass B. Can I create a single array of 20 elements of the class and store the 10 objects of subclass A and 10 of subclass B, or do I need to explicitly create an array of size 10 of the type object of subclass A, and another array of size 10 of the type object of subclass B?
One of the teachers said I could do the first option, create an array of the superclass and store the subclass objects there, but he didn't explicitly tell me how. As we were just introduced to the notion of subclass, I thought there was no catch, seems I was wrong. I've read some articles about subclasses, casting, etc., but I fear I wasn't able to actually understand enough of it.
So, as an example, if I have a class Feline, with subclasses Cat and Lion, and I want to store 10 cats and 10 lions, how can I store them in a 20-sized array of type Feline instead of having two arrays, one for Cat, and one for Lion?
Thanks in advance for the help. It's not that I'm lazy, I'm just new to the stuff and I wanted to know how to do this to get some work done at an early stage.

Answer 1

VascoPatricio wrote:
So, as an example, if I have a class Feline, with subclasses Cat and Lion, and I want to store 10 cats and 10 lions, how can I store them in a 20-sized array of type Feline instead of having two arrays, one for Cat, and one for Lion?Just declare the array to have Felines in it, and then you can add Cats and Lions as you wish.
Feline[] felineArray = new Feline[20]; // This array will hold 20 Felines
felineArray[0] = new Cat(); // Set the first element to a Cat
felineArray[1] = new Cat(); // Set the second element to a Cat
felineArray[9] = new Cat(); // Set the tenth element to a Cat
felineArray[10] = new Lion(); // Set the eleventh element to a Lion
felineArray[11] = new Lion(); // Set the twelfth element to a Lion
felineArray[19] = new Lion(); // Set the twentieth element to a Lion