Check value in array in string

Question

I am creating a takeaway restaurant database, which can be accessed by the Managers of each store. One of the database tables in called Product, and it has a column called product_name. The product_name is a string with multiple words. I'm trying to check whether the product_name contains meat, and then tell the user whether it is or is not suitable for vegetarians.

This is the code I have. I was trying to create a meats array, and check product_name against it. I don't think the if not statement is correct.

class Checkveg
  def self.runcheck(product_name)
    meats = ["lamb", "beef", "pork", "prawn", "chicken", "fish"]
    meats.each { |item|
      if product_name.include? item
        puts "Not suitable for vegans or vegetarians"
      end
    }
    puts "Suitable for vegans or vegetarians" if not meats.include? product_name
  end
end

**UPDATE:

I was able to fix it

noVeg = false
meats = ["lamb", "beef", "pork", "prawn", "chicken", "fish"]
meats.any? { |item|
  if product_name.include? item
    noVeg = true
    break
  end
}
if noVeg == true
  puts "Not suitable for vegetarians"
else
  puts "Suitable for vegetarians"
end

I haven't implemented it get, and i would like input to whether the coding is correct. — TattooedJoey
– TattooedJoey, Commented Mar 16, 2019 at 12:29
meats.include? x is going to be true if x is in the array meats. Do you expect product_name ever to be an element of the array? Also, look up the Ruby Array class. There are other interesting methods such as .any? or .all? that may be of interest for your problem and make it simpler. — lurker
– lurker, Commented Mar 16, 2019 at 12:29
@lurker puts "Suitable for vegans or vegetarians" if not meats.include? product_name. Would that also work, even if the product_name is a string with multiple words? — TattooedJoey
– TattooedJoey, Commented Mar 16, 2019 at 12:31
meats.include? product_name will be true only if product_name is an element of the array meats. I suspect that it never is. Also, see my prior comment about .any? and .all?. — lurker
– lurker, Commented Mar 16, 2019 at 12:32
It took me 1 minute and 27 seconds to load your code into console and run it. Why don't you do the same and see what works and what doesn't? — jvillian
– jvillian, Commented Mar 16, 2019 at 12:33

user000001 · Accepted Answer · 2019-03-16 13:05:14Z

2

You are not using the any? method properly. You should use it's return value like this:

#!/usr/bin/env ruby

meats = ["lamb", "beef", "pork", "prawn", "chicken", "fish"]

product_name = "Beef curry"

noVeg = meats.any? do |item|
    product_name.downcase.include? item
end

if noVeg == true
    puts "Not suitable for vegetarians"
else
    puts "Suitable for vegetarians"
end

I also added downcase since in the comment above you wrote beef with a capital b.

answered Mar 16, 2019 at 13:05

user000001

33.7k14 gold badges86 silver badges113 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

3limin4t0r Over a year ago

if noVeg == true is also an anti-pattern. You could simply do if noVeg.

user000001 Over a year ago

@3limin4t0r true, that's what you get when copying OP's code, the point was to show the any method though.

3limin4t0r Over a year ago

I thought as much. Maybe the comment was better suited under the question itself, but nonetheless it's worth pointing out.

iGian · Accepted Answer · 2019-03-16 15:27:21Z

2

I'd suggest, first to extract the words from the product name. I used the regex from a good example by Cary Swoveland for this method. But you can use whatever regex fits best for you:

product_name = "Chicken_Wings 1"
product_words = product_name.scan(/[[:alpha:]](?:(?:[[:alpha:]]|\d|')*[[:alpha:]])?/x).map(&:downcase)

#=> ["chicken", "wings"]

Then check if none of the product_words is included in meats array:

no_veg = product_words.none? { |w| meats.include? w }
#=> false

In this case product_name = "Carrots and onions", no_veg = true.

edited Mar 16, 2019 at 15:27

answered Mar 16, 2019 at 14:17

iGian

11.2k3 gold badges24 silver badges38 bronze badges

1 Comment

3limin4t0r Over a year ago

When using this approach you could also use (product_words & meats).empty? instead of product_words.none? { |w| meats.include? w }. Although the result would be the reverse, eg. veg.

3limin4t0r · Accepted Answer · 2019-03-16 16:32:12Z

2

Another option is to create a regex using the meats array.

meats_regex_string = meats.map(&Regexp.method(:escape)).join('|')
meats_regex = Regexp.new(meats_regex_string)
# or /#{meats_regex_string}/
product_name.match?(meats_regex)

You can leave out .map(&Regexp.method(:escape)) if you know your strings don't contain any regex special characters like (, *, ?, |, etc.

If you don't care about the character casing use:

meats_regex = Regexp.new(meats_regex_string, Regexp::IGNORECASE)
# or /#{meats_regex_string}/i

edited Mar 16, 2019 at 16:32

answered Mar 16, 2019 at 16:16

3limin4t0r

21.4k3 gold badges38 silver badges61 bronze badges

1 Comment

3limin4t0r Over a year ago

Since you're new to Ruby it might be worth pointing out that .map(&Regexp.method(:escape)) could also be written as .map { |meat| Regexp.escape(meat) }.

Collectives™ on Stack Overflow

Check value in array in string

3 Answers 3

3 Comments

1 Comment

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

3 Comments

1 Comment

1 Comment

Your Answer

Sign up or log in

Post as a guest