CODEWITHSUNDEEP
ruby
chris Frisina
chris Frisina

Reputation: 19688

Convert string numbers( in word format) to integer ruby

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?

Upvotes: 4

Views: 7329

Answers (4)

Jesson Foo
Jesson Foo

Reputation: 74

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))

Upvotes: 3

rohit89
rohit89

Reputation: 5773

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

Upvotes: 12

the Tin Man
the Tin Man

Reputation: 160559

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"

Upvotes: -2

sawa
sawa

Reputation: 168101

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

Upvotes: 1

Related Questions