How to Split (Chunk) a Ruby Array into Parts of X Elements

How to split (chunk) a Ruby array into parts of X elements?

Take a look at Enumerable#each_slice:

foo.each_slice(3).to_a
#=> [["1", "2", "3"], ["4", "5", "6"], ["7", "8", "9"], ["10"]]

Dividing elements of a ruby array into an exact number of (nearly) equal-sized sub-arrays

You're looking for Enumerable#each_slice

a = [0, 1, 2, 3, 4, 5, 6, 7]
a.each_slice(3) # => #<Enumerator: [0, 1, 2, 3, 4, 5, 6, 7]:each_slice(3)>
a.each_slice(3).to_a # => [[0, 1, 2], [3, 4, 5], [6, 7]]

Need to split arrays to sub arrays of specified size in Ruby

arr.each_slice(3).to_a

each_slice returns an Enumerable, so if that's enough for you, you don't need to call to_a.

In 1.8.6 you need to do:

require 'enumerator'
arr.enum_for(:each_slice, 3).to_a

If you just need to iterate, you can simply do:

arr.each_slice(3) do |x,y,z|
  puts(x+y+z)
end

How to split an array into n equal or close to equal arrays?

a = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]

a.group_by.with_index{|_, i| i % 2}.values
# => [[1, 3, 5, 7, 9], [2, 4, 6, 8, 10]]

a.group_by.with_index{|_, i| i % 3}.values
# => [[1, 4, 7, 10], [2, 5, 8], [3, 6, 9]]

a.group_by.with_index{|_, i| i % 4}.values
# => [[1, 5, 9], [2, 6, 10], [3, 7], [4, 8]]

a.group_by.with_index{|_, i| i % 5}.values
# => [[1, 6], [2, 7], [3, 8], [4, 9], [5, 10]]

a.group_by.with_index{|_, i| i % 6}.values
# => [[1, 7], [2, 8], [3, 9], [4, 10], [5], [6]]

How do I split an array into smaller arrays bsaed on a condition?

One more way to skin a cat

def contains_vowel(v) 
   v.count("aeiou") > 0
end 
def split_by_substring_with_vowels(arr)
  arr.chunk_while do |before,after|
    !contains_vowel(before) & !contains_vowel(after)
  end.to_a
end
split_by_substring_with_vowels(arr)
#=> [["a"], ["b", "g"], ["e"], ["f", "h"], ["i"]]

What it does:

• passes each consecutive 2 elements
• splits when either of them contain vowels

Example with your other Array

arr = ["1)", "dwr", "lyn,", "18,", "bbe"]
split_by_substring_with_vowels(arr)
#=> [["1)", "dwr", "lyn,", "18,"], ["bbe"]]

Further example: (if you want vowel containing elements in succession to stay in the same group)

def split_by_substring_with_vowels(arr)
  arr.chunk_while do |before,after|
    v_before,v_after = contains_vowel(before),contains_vowel(after)
    (!v_before & !v_after) ^ (v_before & v_after)
  end.to_a
end

arr = ["1)", "dwr", "lyn,", "18,", "bbe", "re", "rr", "aa", "ee"]
split_by_substring_with_vowels(arr)
#=> [["1)", "dwr", "lyn,", "18,"], ["bbe", "re"], ["rr"], ["aa", "ee"]]

This checks if before and after are both not vowels Or if they both are vowels

Splitting array in three different arrays of maximum three elements

Try this...
Using Enumerable#each_slice to slice array x value

array  = [12, 13, 14, 18, 17, 19, 30, 23]
array.each_slice(3)
array.each_slice(3).to_a 

How to chunk an array in Ruby

Use each_slice:

require 'enumerator' # only needed in ruby 1.8.6 and before
userids.each_slice(100) do |a|
  # do something with a
end

Split an array in ruby based on some condition

Try the partition method

@arr1, @arr2 = @level1.partition { |x| x[0] > 2.1 }

The condition there may need to be adjusted, since that wasn't very well specified in the question, but that should provide a good starting point.

Split an array into some sub-arrays

You can use the #each_slice method on the array

big_array = (0..20).to_a
array = big_array.each_slice(2).to_a
puts array # [[0, 1], [2, 3], [4, 5], [6, 7], [8, 9], [10, 11], [12, 13], [14, 15], [16, 17], [18, 19], [20]]

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