Convert string numbers( in word format) to integer ruby

Question

If you have a string ten, is it possible to convert it to an integer 10 in Ruby? (maybe in rails?)

I value the developers at tryruby.org, and in their tutorial here, it specifically says "to_i converts things to integers (numbers.)" I am wondering why they didn't say "to_i converts STRINGS to integers (numbers.)"

What variable types can be converted from their type to an integer?

score 11 · Accepted Answer · edited Dec 24 '13 at 10:59

11

Check out this gem for handling word to number conversions.

From the readme:

require 'numbers_in_words'
require 'numbers_in_words/duck_punch'

112.in_words
#=> one hundred and twelve
"Seventy million, five-hundred and fifty six thousand point eight nine three".in_numbers
#=> 70556000.893

edited Dec 24 '13 at 10:59

Seanny123

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answered Nov 29 '12 at 18:44

rohit89

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Jesson Foo · Answer 2 · 2014-07-11T02:16:42.467

How I would have done it.

def n_to_s(int)

    set1 = ["","one","two","three","four","five","six","seven",
         "eight","nine","ten","eleven","twelve","thirteen",
         "fourteen","fifteen","sixteen","seventeen","eighteen",
         "nineteen"]

    set2 = ["","","twenty","thirty","forty","fifty","sixty",
         "seventy","eighty","ninety"]

    thousands = (int/1000)
    hundreds = ((int%1000) / 100)
    tens = ((int % 100) / 10)
    ones = int % 10
    string = ""

    string += set1[thousands] + " thousand " if thousands != 0 if thousands > 0
    string += set1[hundreds] + " hundred" if hundreds != 0
    string +=" and " if tens != 0 || ones != 0 
    string = string + set1[tens*10+ones] if tens < 2
    string += set2[tens]
    string = string + " " + set1[ones] if ones != 0     
    string << 'zero' if int == 0    
    p string
end

for the purpose of testing;

n_to_s(rand(9999))

sawa · Answer 3 · 2012-11-26T12:27:52.923

1

Since String#to_i picks out only the number characters, it will not work in the way you want. There may be some Rails method related to that, but it surely will not have the method name to_i because its behavior will conflict with the original intent of String#to_i.

It is not only Strings that has to_i. NilClass, Time, Float, Rational (and perhaps some other classes) do as well.

"3".to_i #=> 3
"".to_i #=> 0
nil.to_i #=> 0
Time.now.to_i #=> 1353932622
(3.0).to_i #=> 3
Rational(10/3).to_i #=> 3

edited Nov 26 '12 at 12:27

answered Nov 26 '12 at 12:22

sawa

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seems OP means `ten` to 10, `nine` to 9 etc :) – Nov 26 '12 at 12:24
2

@slivu The OP is asking multiple questions. I am only answering the last one. – sawa Nov 26 '12 at 12:26

score -3 · Answer 4 · answered Nov 26 '12 at 13:18

-3

This is a simple lookup of strings to their numeric equivalent:

str_to_int_hash = {
  'zero'  => 0,
  'one'   => 1,
  'two'   => 2,
  'three' => 3,
  'four'  => 4,
  'five'  => 5,
  'six'   => 6,
  'seven' => 7,
  'eight' => 8,
  'nine'  => 9,
  'ten'   => 10
}

str_to_int_hash['ten']
=> 10

It's obvious there are many other missing entries, but it illustrates the idea.

If you want to go from a number to the string, this is the starting point:

int_to_str_hash = Hash[str_to_int_hash.map{ |k,v| [v,k] }]
int_to_str_hash[10]
=> "ten"

answered Nov 26 '12 at 13:18

the Tin Man

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While this is a starting point for small values, it doesn't hint at the generalities that would be necessary to extend it to arbitrarily large numbers. – Michael Nov 27 '12 at 08:44
That's why I said "simple lookup". Since the OP doesn't mention anything beyond a simple number, in a very confusing and poorly asked question, this suffices. Beyond this it'll need a much more thorough piece of code. – the Tin Man Nov 27 '12 at 14:17

Convert string numbers( in word format) to integer ruby

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