Class: Integer

Inherits:
Object show all
Defined in:
lib/nutella/core_ext/integer/digits.rb,
lib/nutella/core_ext/integer/format.rb,
lib/nutella/core_ext/integer/multiples.rb

Instance Method Summary collapse

Instance Method Details

#digits ⇒ Array

Returns an array of integers containing the digits of the integer. The "-" will be trimmed if the number is negative.

120.digits  # => [1, 2, 0]
-35.digits  # => [3, 5]

Returns:

  • (Array) —

    the digits of the number as integers



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# File 'lib/nutella/core_ext/integer/digits.rb', line 9

def digits
  abs.to_s.chars.map &:to_i
end

#goes_into?(*nums) ⇒ Boolean

Checks whether the integer goes evenly into all of the arguments.

Examples:

Check if 3 goes into some numbers

3.goes_into? 10  # => false
3.goes_into? 6   # => true

Check if 5 goes into every number in some sets of numbers

5.goes_into? 10, 12  # => false
5.goes_into? 10, 20  # => true

Parameters:

  • nums (*Integer) —

    the integer(s) to check against

Returns:

  • (Boolean) —

    whether or not the integer goes evenly into all of the arguments



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# File 'lib/nutella/core_ext/integer/multiples.rb', line 15

def goes_into?(*nums)
  nums.all? { |n| (!zero? && n % self == 0) || n.zero? }
end

#goes_into_any?(*nums) ⇒ Boolean

Checks whether the integer goes evenly into any of the arguments.

Examples:

Check if 5 goes into every number in some sets of numbers

5.goes_into_any? 10, 20  # => true
5.goes_into_any? 10, 12  # => true
5.goes_into_any? 12, 21  # => false

Parameters:

  • nums (*Integer) —

    the integer(s) to check against

Returns:

  • (Boolean) —

    whether or not the integer goes evenly into any of the arguments



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# File 'lib/nutella/core_ext/integer/multiples.rb', line 29

def goes_into_any?(*nums)
  nums.any? { |n| goes_into? n }
end

#multiple_of?(*nums) ⇒ Boolean Also known as: divisible_by?

Checks whether the integer is evenly divisible by all of the arguments.

Examples:

Check if some numbers are evenly divisible by 5

4.multiple_of? 5   # => false
30.multiple_of? 5  # => true

Check if some numbers are evenly divisible by both 4 and 7

10.multiple_of? 4, 7  # => false
56.multiple_of? 4, 7  # => true

Parameters:

  • nums (*Integer) —

    the integer(s) to check against

Returns:

  • (Boolean) —

    whether or not the integer is evenly divisible by all arguments



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# File 'lib/nutella/core_ext/integer/multiples.rb', line 46

def multiple_of?(*nums)
  nums.all? { |n| (!n.zero? && self % n == 0) || zero? }
end

#multiple_of_any?(*nums) ⇒ Boolean Also known as: divisible_by_any?

Checks whether the integer is evenly divisible by any of the arguments.

Examples:

Project Euler #1 solution using Nutella

(1...1000).sum { |n| n.multiple_of_any?(3, 5) }

Parameters:

  • nums (*Integer) —

    the integer(s) to check against

Returns:

  • (Boolean) —

    whether or not the integer is evenly divisible by any arguments



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# File 'lib/nutella/core_ext/integer/multiples.rb', line 59

def multiple_of_any?(*nums)
  nums.any? { |n| multiple_of? n }
end

#ordinalize ⇒ String

Returns a string with the ordinal form of the integer.

1.ordinalize   # => "1st"
2.ordinalize   # => "2nd"
9.ordinalize   # => "9th"
43.ordinalize  # => "43rd"

Returns:

  • (String) —

    the ordinal form of the integer



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# File 'lib/nutella/core_ext/integer/format.rb', line 10

def ordinalize
  self.to_s + if abs % 100 / 10 != 1 && (1..3).include?(last = abs % 10)
    {1 => "st", 2 => "nd", 3 => "rd"}[last]
  else
    "th"
  end
end