Class: Array

Inherits:
Object
  • Object
show all
Defined in:
lib/extensions/array.rb

Instance Method Summary collapse

Instance Method Details

#sample(arr = nil) ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/extensions/array.rb', line 3

def sample(arr = nil)
  # based on code from https://github.com/marcandre/backports
  size = length
  return self[Kernel.rand(size)] if arr.nil?

  arr = arr.to_int
  raise ArgumentError, 'negative array size' if arr < 0

  arr = size if arr > size

  result = Array.new(self)
  arr.times do |i|
    r = i + Kernel.rand(size - i)
    result[i], result[r] = result[r], result[i]
  end
  result[arr..size] = []
  result
end