class MoneyMaahd

This class is used to convert currencies and do some simple math.

Attributes

amount[RW]

reader and writer for both class and instance variables

base_currency[RW]

reader and writer for both class and instance variables

currency[RW]

reader and writer for both class and instance variables

rates[RW]

reader and writer for both class and instance variables

Public Class Methods

conversion_rates(base_currency, rates = {}) click to toggle source

define class method for assigning base currency and exchange rates

# File lib/money_maahd.rb, line 20
def self.conversion_rates(base_currency, rates = {})
  @@base_currency = base_currency
  @@rates = rates
end

new(amount, currency) click to toggle source

initialize with instance variables

# File lib/money_maahd.rb, line 9
def initialize(amount, currency)
  @amount = amount
  @currency = currency
end

Public Instance Methods

*(right) click to toggle source

override the multiply operator

# File lib/money_maahd.rb, line 55
def *(right)
  product = @amount * right
  MoneyMaahd.new('%.2f' % [product], @currency)
end

+(right) click to toggle source

override the plus operator

# File lib/money_maahd.rb, line 35
def +(right)
  right_in_base_currency = right.convert_to(@@base_currency)
  sum = @amount + right_in_base_currency.amount.to_f
  MoneyMaahd.new('%.2f' % [sum], @@base_currency)
end

-(right) click to toggle source

override the subtraction operator

# File lib/money_maahd.rb, line 42
def -(right)
  right_in_base_currency = right.convert_to(@@base_currency)
  difference = @amount - right_in_base_currency.amount.to_f
  MoneyMaahd.new('%.2f' % [difference], @@base_currency)
end

/(right) click to toggle source

override the division operator

# File lib/money_maahd.rb, line 49
def /(right)
  quotient = @amount / right
  MoneyMaahd.new('%.2f' % [quotient], @currency)
end

<(right) click to toggle source

override the is less than operator

# File lib/money_maahd.rb, line 83
def <(right)
  if self.currency == right.currency
    self.amount < right.amount
  else #if left is not base currency
    left = self.convert_to(@@base_currency)
    left_amount = left.amount.to_f
    left_amount < right.amount
  end
end

==(right) click to toggle source

override the is equal operator

# File lib/money_maahd.rb, line 61
def ==(right)
  if right.currency == @currency
    @amount == right.amount
  else
    left = self.convert_to(@@base_currency)
    left_amount = left.amount.to_f
    left_amount == right.amount
  end
end

>(right) click to toggle source

override the is greater than operator

# File lib/money_maahd.rb, line 72
def >(right)
  if self.currency == right.currency
    self.amount > right.amount
  else # if left is not base currency
    left = self.convert_to(@@base_currency)
    left_amount = left.amount.to_f
    left_amount > right.amount
  end
end

convert_to(currency) click to toggle source

converts to a different currency

# File lib/money_maahd.rb, line 26
def convert_to(currency)
  if currency != @@base_currency
    MoneyMaahd.new('%.2f' % [@amount * @@rates[currency]], currency)
  else
    MoneyMaahd.new('%.2f' % [@amount.to_f / @@rates[@currency]], currency)
  end
end

inspect() click to toggle source

override the inspect method

# File lib/money_maahd.rb, line 15
def inspect
  '%.2f' % [@amount] + " " + @currency
end