Instance variable functions

Question

1. What is the difference between including @cards as an argument in the initialize method vs. not including it as an argument?

2. For the class Player below does not including @cards as an argument in the initialize method mean that all instances of the class (in other words each player) will have the same number of cards?

3. Can I set each player to have a different number of cards later without modifying the code below?

class Player
def initialize (name)
@name = name
@cards = []
end
end

player1 = Player.new("Kuba")

Answer 1

Having an argument allows each instance to start with a different set of array elements. However, you can add elements to the array later without issue. Your code currently makes the array with no elements. You can:
def add(element)
@cards.push(element)
end

player1.add('5s')