Class: Integer

Inherits:
Object show all
Defined in:
lib/more_ruby/integer.rb

Instance Method Summary collapse

Instance Method Details

#digit_count ⇒ Object

Returns the number of digits in the number



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# File 'lib/more_ruby/integer.rb', line 6

def digit_count
    self.to_s.size
end

#num_to_letter ⇒ Object

Converts the number (1 <= x <= 26) to a letter 1 => A, 9 => I, 0 has no corresponding letter



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# File 'lib/more_ruby/integer.rb', line 23

def num_to_letter
    raise "Do not call num_to_letter with a number that is not between 1 and 26" unless self >= 1 && self <= 26
    (self.to_i + 64).chr
end

#signif(num_digits) ⇒ Object

Code taken from www.ruby-forum.com/topic/187036 ; all credit for mechanism goes to Harry Kakueki Method is same as Float#signif below; dangerous to add to common parent Numeric?

Raises:

  • (TypeError) 


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# File 'lib/more_ruby/integer.rb', line 12

def signif(num_digits)
    raise TypeError, "Must call #{__method__} with an Integer" unless num_digits.kind_of?(Integer)
    raise ArgumentError, "Must call #{__method__} with a positive Integer" if num_digits < 0 # 0 is a special case, but allowed
    return 0.0 if num_digits == 0
    return self if self.digit_count <= num_digits
    m = (num_digits - 1) - Math.log10(self.abs).floor
    BigDecimal.new(((self * 10 ** m).round * 10 ** (-1 * m)).to_s).to_s('F').gsub(/\.0*$/,"").to_i
end