CODEWITHSUNDEEP
rubyarrays
user3643195
user3643195

Reputation: 35

split the contents of the array into two other arrays

Simple example but I want to understand how it is done so I can apply it else where I have a main array with 6 elements. I want to take 3 of the elements from the main array and put it in a array and then take the other 3 from main array and put them in b array. I will use this to apply it to dealing cards to two players

main = [1, 2, 3, 4, 5, 6]
    a = [ ] 
    b = [ ]

Upvotes: 1

Views: 109

Answers (4)

Gagan Gami
Gagan Gami

Reputation: 10251

All may have given the right answer, But as I understood from your question (I will use this to apply it to dealing cards to two players) When you dealing cards, as you deal cards to player main array should remove that element from self array to overcome Redundancy Problem (duplication). When you deal the all cards main array must be empty.

For this solution have a look at Array#shift

> main = [1,2,3,4,5,6]  # I have 6 cards on my hand before dealing cards to players
 => [1, 2, 3, 4, 5, 6] 
> a = main.shift(3)  # given 3 cards to Player a
 => [1, 2, 3] 
> b = main.shift(3)  # given 3 cards to Player b
 => [4, 5, 6] 
> main  # after dealing all cards to two players I should not have any card on my hand
 => []

Upvotes: 1

daremkd
daremkd

Reputation: 8424

You have many ways to do the same thing in Ruby. Splitting arrays isn't an exception. Many answers (and comments) told you some of the ways to do that. If your program is dealing cards, you won't stop there. First, you'll probably have more than 6 cards. Second, you're probably going to have more than 2 players. Let's say the cards are C and the players are P. You need to write a method that, no matter how many Cs or Ps there are, the method is going to give each Player an equal number of Ccards (or return an error if it can't give it an equal number of cards). So for 6 cards and 2 players, it will give 3 cards each. For 12 cards and 3 players, 4 cards each. For 3 cards and 2 players, it's going to produce an error because the cards can't be evenly split:

def split_cards_evenly_between_players(cards, players)
  if cards.size % players != 0
    raise 'Cannot split evenly!'
  else
    groups_to_split_into = cards.size / players
    cards.each_slice(groups_to_split_into).to_a
  end
end

Let's go through the code. If the cards can't be evenly split between players, then the remainder by dividing them won't be 0 (6 cards / 3 players = remainder 0. 7 cards / 3 players = remainder 1). That's what line 2 checks. If the cards CAN be split, then we first find the groups to split into (which is dividing the number of cards by the number of players). Then we just split the array into that many groups with Enumerable#each_slice. Finally, since this doesn't produce an array, we need .to_a to convert it. The return value in Ruby is always the value of the last expression executed. The only expression in this method is the if/then expression which also returns the value of the last expression executed (which is the line where each_slice is). Let's try it out:

p split_cards_evenly_between_players([1,2,3,4,5,6,7,8,9,10,11,12],2) #=> [[1, 2, 3, 4, 5, 6], [7, 8, 9, 10, 11, 12]]
p split_cards_evenly_between_players([4,5,1,2,5,3], 3) #=> [[4, 5], [1, 2], [5, 3]]
p split_cards_evenly_between_players([1,2,3],2) #=> Error: Cannot split evenly!

The nice thing about Ruby is its simple syntax and the fact it tries to get out of your way while solving a problem so you can focus more on the actual problem than the code.

Upvotes: 0

scottxu
scottxu

Reputation: 933

main = [1, 2, 3, 4, 5, 6]
#=> [1, 2, 3, 4, 5, 6] 
main.first(3)
#=> [1, 2, 3] 
main.last(3)
#=> [4, 5, 6]

Upvotes: 4

Jin
Jin

Reputation: 13463

a = [1, 2, 3, 4, 5, 6]
#=> [1, 2, 3, 4, 5, 6]
b = a.take(3)
#=> [1, 2, 3]
c = a.drop(3)
#=> [4, 5, 6]

Upvotes: 1

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