class Integer
Public Instance Methods
is_prime?()
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# File lib/multiply_prime_numbers_table/prime.rb, line 3 def is_prime? # Avoid to check number if is negative, is 1 or is EVEN distinct of 2 return false if self <= 1 || (self.even? && self > 2) # returns false if the module dividing num by other number from 2 to the square root of itsel is zero 2.upto(Math.sqrt(self).to_i) do |integer| return false if (self % integer).zero? end # if none of the previous checks match it means it's a prime number true end