CODEWITHSUNDEEP
ruby-on-railsruby
Gandalf StormCrow
Gandalf StormCrow

Reputation: 26222

Splitting/Slicing array in ruby

I've found this similar two questions to the one I'm about to ask:

Split array up into n-groups of m size? and Need to split arrays to sub arrays of specified size in Ruby

This splits array into three arrays with each array having three elements :

a.each_slice(3) do |x,y,z|
  p [x,y,z]
end

So if I do this (my array size is 1000) :

a.each_slice(200) do |a,b,c,d,e|
            p "#{a} #{b} #{c} #{d} #{e}"
        end

This should split my array into 5 arrays each having 200 members? But it doesn't? What I actually need to do is to put 200 random elements into 5 arrays, am I on the right track here, how can I do this?

Upvotes: 1

Views: 1118

Answers (4)

fmendez
fmendez

Reputation: 7338

If you want to assign that result to 5 different arrays, you could use the splat operator,like this:

a,b,c,d,e = *(1..1000).each_slice(200).to_a

Upvotes: 0

Cluster
Cluster

Reputation: 5626

Enumerable#each_slice

If you provide a single argument to the block of each_slice then it will fill that argument with an array of values less than or equal to the given argument. On the last iteration if there are less than n values left then the array size will be whatever is left.

If you provide multiple arguments to the block of each_slice then it will fill those values with the values from the source array. If the slice size is greater than the number of arguments given then some values will be ignored. If it is less than the number of arguments than the excess arguments will be nil.

a = (1..9).to_a

a.each_slice(3) {|b| puts b.inspect }
[1,2,3]
[4,5,6]
[7,8,9]

a.each_slice(4) {|b| puts b.inspect }
[1,2,3,4]
[5,6,7,8]
[9]

a.each_slice(3) {|b,c,d| puts (b + c + d)}
6   # 1 + 2 + 3
15  # 4 + 5 + 6
24  # 7 + 8 + 9

a.each_slice(3) {|b,c| puts (b + c)}
3   # 1 + 2, skips 3
9   # 4 + 5, skips 6
15  # 7 + 8, skips 9

a.each_slice(2) {|b,c| puts c.inspect}
2
4
6
8
nil

a.each_slice(3) {|b,c,d,e| puts e.inspect}
nil
nil
nil

Upvotes: 2

nurettin
nurettin

Reputation: 11756

irb(main):001:0> a= (1..10).to_a
=> [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
irb(main):002:0> a.sample(3)
=> [5, 10, 1]
irb(main):003:0> (1..3).map{ a.sample(3) }
=> [[6, 2, 5], [8, 7, 3], [4, 5, 7]]
irb(main):004:0>

Upvotes: 1

Angelos Kapsimanis
Angelos Kapsimanis

Reputation: 999

Actually you will return a string with the five elements inserted in it. You can try something:

a1 = [], a2 = [], a3 = [], a4 = [], a5 = []

a.each_slice(5) do |a,b,c,d,e|
  a1 << a
  a2 << b
  a3 << c
  a4 << d
  a5 << e
end

You will end up with five arrays containing 200 elements each. I used the simplest possible syntax to make it clear, you can make it much more condensed.

Upvotes: 0

Related Questions