So I'm writing what I thought was a simple .rb file to convert a float number into a string. The string returns my floating point number in words. So if I have 11.11 then I would have eleven dollars and eleven cents So far I've extended the float class which has worked alright. I'm having trouble with how to convert the 11 cents into eleven cents. en.numwords would kick back eleven point one one. I've thought about trying out a hash to solve my problem where 11=>eleven cents. Any thoughts how I could implement this? Perhaps a better way to implement this?
Here's what I have so far:
require 'rubygems'
require 'linguistics'
Linguistics::use( :en )
class Float
def to_test_string
puts self #check
puts self.en.numwords
self.en.numwords
end
end
puts "Enter two great floating point numbers for adding"
puts "First number"
c = gets.to_f
puts "Second number"
d = gets.to_f
e = c+d
# puts e
puts e.to_test_string
puts "Enter a great floating number! Example 10.34"
a = gets.to_f
# puts a
puts a.to_test_string
Thanks for the help! Post some code so I can try ideas out!
Here's one solution: divide the number into two substrings based on the decimal point delimiter, call en.numwords on each substring separately, and then join the resulting strings with "point" between them. Something along the lines of:
require "rubygems"
require "linguistics"
Linguistics::use(:en)
class Float
def my_numwords
self.to_s.split('.').collect { |n| n.en.numwords }.join(' point ')
end
end
(11.11).my_numwords # => eleven point eleven
This problem can be solved by splitting the float into two values: dollars and cents.
require 'rubygems'
require 'linguistics'
Linguistics::use( :en )
class Float
def to_test_string
puts self #check
#Split into dollars and cents
cents = self % 1
dollars = self - cents
cents = cents * 100
text = "#{dollars.to_i.en.numwords} dollars and #{cents.to_i.en.numwords} cents"
puts text
text
end
end
puts "Enter two great floating point numbers for adding"
puts "First number"
c = gets.to_f
puts "Second number"
d = gets.to_f
e = c+d
# puts e
puts e.to_test_string
puts "Enter a great floating number! Example 10.34"
a = gets.to_f
# puts a
puts a.to_test_string
Related
Using Ruby why can't I pass random variable here? I tried different combinations such as removing numbers.
money= rand(100)
def paycheck(money)
"Lets make this amount, #{money} today"
end
puts paycheck("100")
puts paycheck("200")
puts paycheck("500")
You can:
money= rand(100)
puts paycheck(money)
When you define your method paycheck(money) - it is different variable money that the one on this line: money = rand(100)
You can do something like this:
def paycheck(limit)
money = rand(limit.to_i)
"Lets make this amount, #{money} today"
end
puts paycheck("100") #=> Lets make this amount, 14 today
puts paycheck("200") #=> Lets make this amount, 111 today
puts paycheck("500") #=> Lets make this amount, 119 today
First post, excuse if I break any etiquette. I am beginning, so this might be simple.
Trying to code in ruby, a calculator, where user inputs arithmetic sentence (only binary, PEMDAS/BIDMAS will do later) and the answer comes out.
Here is my code, by only works for single digit numbers.
class Calculator
def initializer (a,b)
#a = a,
#b = b
end
def add(a, b)
a+b
end
def subtract(a, b)
a-b
end
def multiply(a,b)
a*b
end
def divide (a,b)
a/b
end
def powers (a,b)
a**b
end
end
puts "Enter an expression to be evaluated"
a = gets.chomp.gsub(/\s+/, "")
puts case a[1]
when "+"
"#{a[0]} + #{a[2]} = #{Calculator.new.add(a[0].to_f,a[2].to_f)}"
when "-"
"#{a[0]} - #{a[2]} = #{Calculator.new.subtract(a[0].to_f,a[2].to_f)}"
when "*" || "x" || "X"
"#{a[0]} x #{a[2]} = #{Calculator.new.multiply(a[0].to_f,a[2].to_f)}"
when "/"
"#{a[0]} / #{a[2]} = #{Calculator.new.divide(a[0].to_f,a[2].to_f)}"
when "^"
"#{a[0]} to the power #{a[2]} = #Calculator.new.powers(a[0].to_f,a[2].to_f)}"
else
"Not valid"
end
I was thinking of trying to split a string like "234+342" (234 and 342 can be any sized length numbers) into an array such as ["234","+","342"].
But I am stuck on how to do this??? Or is there another way??
Help will be appreciated, just a personal challenge.
Thanks
As you already realized the issue is with the way you are carrying operations over input string.
The simplest way to proceed can be to ask users for two numbers and then ask them to enter the operation needed. Something like:
puts "Enter first number"
a = gets.chomp
puts "Enter second number"
b = gets.chomp
puts "Enter required operation [+, -, *, /]"
c = gets.chomp
You can do this all in one shot too, the way you are already trying, however I would advice against it as you never know what user will enter. Eg:
puts "Enter an expression to be evaluated"
a = gets.chomp # user enters: 123 + 457
# => "123 + 457"
Now extracting number:
numbers = a.scan(/\d+/)
#=> ["123", "457"]
operator = a[/\W+/]
#=> " + "
You can then proceed with your switch case.
def percent_more
puts "What is the biggest number?"
biggest_number = gets.chomp
puts "What is the smallest number?"
smallest_number = gets.chomp
difference = biggest_number.to_i - smallest_number.to_i
total_percent_more = difference / smallest_number.to_f
puts "Your biggest number is #{total_percent_more}% bigger then your smallest number. Don't forget to round off to the nearest whole percent!"
end
Now that code will tell you what percent more biggest_number is than smallest_number. But the problem is it prints out a long list of decimals, which are a pain to sort through. So if I wanted the code to only show say the first 3 numbers what would I do??
What you want to use is total_percent_more.round like so:
puts "What is the biggest number?"
biggest_number = gets.chomp
puts "What is the smallest number?"
smallest_number = gets.chomp
difference = biggest_number.to_i - smallest_number.to_i
total_percent_more = difference / smallest_number.to_f
puts "Your biggest number is #{total_percent_more.round}% bigger then your smallest number. Don't forget to round off to the nearest whole percent!"
See the docs for more info :
http://www.ruby-doc.org/core-2.1.2/Float.html#method-i-round
in ruby versions earlier than 1.9 you'll need to use sprintf like so:
puts "Your biggest number is #{sprintf('%.2f', total_percent_more)}% bigger then your smallest number. Don't forget to round off to the nearest whole percent!"
You can change the amount of decimal places by changing the number.
See docs for more details:
http://www.ruby-doc.org/core-1.8.7/Kernel.html#method-i-sprintf
result = 10/6.0
puts result
printf("%.3f\n", result)
--output:--
1.66666666666667
1.667
Here is an example how to round to 2 decimal places
amount = 342
puts amount.round(2)
If you wanted to round to the nearest 3 decimal places then something like:
puts amount.round(3)
I'm making a interest calculator
I go 10 * .10 * 10 and i get 0 so how do i multiply a decimal without it being 0?
my source code is
def interest()
puts "Type the original loan."
loan = gets.chomp.to_i
puts "Type the amount of interest in decimal."
interest = gets.chomp.to_i
puts "How many years?"
years = gets.chomp.to_i
puts "Your interest is"
puts loan * interest * years
end
interest()
You've got integers there, so result will be an integer too. You could use 'to_f but beware, it's not good for dealing with money or anything else needing precision. Use BigDecimal instead:
require 'bigdecimal'
def interest
puts "Type the original loan."
loan = BigDecimal(gets.chomp)
puts "Type the amount of interest in decimal."
interest = BigDecimal(gets.chomp)
puts "How many years?"
years = BigDecimal(gets.chomp) # suggested in comment, agreed with that
puts "Your interest is"
puts loan * interest * years
end
What's the difference between them?
Do this
interest = gets.chomp.to_f
.to_i changes the string to an integer. An integer is a WHOLE number.
.to_f is to float, a float is a number that allows decimal places
The problem is that you're using .to_i when you don't really want to use integers here. Integers are represented without decimal parts to them, and therefore when you call .10.to_i it truncates it to 0.
Consider using floats by .to_f instead
So I'm trying some code out to convert numbers into strings. However, I noticed that in certain cases it does not preserve the last two decimal places. For instance I type 1.01 and 1.04 for addition and I get back 2.04. If I type just 1.05 it preserves the number and returns it exactly. I get whats going on things are being rounded. I don't know how to prevent it from being rounded though. Should I just consider sending (1.01+1.04) to self as only one input?
Warning! I haven't tried this yet so don't know if its supported:
user_input = (1.04+1.01) #entry from user
user_input = gets.to_f
user_input.to_test_string
What I have so far:
class Float
def to_test_string
cents = self % 1
dollars = self - cents
cents = cents * 100
text = "#{dollars.to_i.en.numwords} dollars and #{cents.to_i.en.numwords} cents"
puts text
text
end
end
puts "Enter two great floating point numbers for adding"
puts "First number"
c = gets.to_f
puts "Second number"
d = gets.to_f
e = c+d
puts e.to_test_string
puts "Enter a great floating number! Example 10.34"
a = gets.to_f
puts a.to_test_string
Thanks for the help! Post some code up so I can try!
First of all: never use float for money — Use Float or Decimal for Accounting Application Dollar Amount?
irb> x = 1.01 + 1.04
=> 2.05
irb> y = x % 1
=> 0.04999999999999982
irb> (y * 100).to_i
=> 4
But if want it VERYVERYVERY much:
irb> (y * 100).round.to_i
=> 5
$ python
Python 2.6.2 (release26-maint, Apr 19 2009, 01:56:41)
[GCC 4.3.3] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> 1.04+1.01
2.0499999999999998
Read this: What Every Computer Scientist Should Know About Floating-Point Arithmetic
Also, what Nakilon said.
This is not a problem with ruby, nor your code (although you need to get rid of .en.numwords); it is a problem with the binary floating point representation.
You should use a Fixnum or Bignum to represent the currency.
eg.
class Currency
def initialize str
unless str =~ /([0-9]+)\.([0-9]{2})/
raise 'invalid currency string'
end
#cents = $1.to_i * 100 + $2.to_i
end
end