Comparing variable to multiple values

ruby-talk
1

I'm wondering if there's a better way to do this in ruby:

if a == "word1" || a == "word2" or || a == "word3"
  puts "good"
end

···

--
Posted via http://www.ruby-forum.com/.

2

Greg Lazarev wrote:

I'm wondering if there's a better way to do this in ruby:

if a == "word1" || a == "word2" or || a == "word3"
  puts "good"
end

if ["word1", "word2", "word3"].include?(a)
   puts 'good'
end

OR

case a
when "word1", "word2", "word3"
  puts 'good'
end

hth
a

3

strings_array = ['word1', 'word2', 'word3']
a = 'word1'
puts "good" if strings_array.include?(a)

4

Greg Lazarev <russianbandit@gmail.com> writes:

I'm wondering if there's a better way to do this in ruby:

if a == "word1" || a == "word2" or || a == "word3"
  puts "good"
end

I realize that you probably want a more general solution (which others
have already provided); however, if 'a' *does* follow a pattern:

puts 'good' if a =~ /word[1-3]/

or

puts 'good' if a =~ /word\d+/

···

--
Brian Adkins
http://www.lojic.com/

5

# I'm wondering if there's a better way to do this in ruby:
# if a == "word1" || a == "word2" or || a == "word3"
# puts "good"
# end

ruby allows you to beautify :wink:

def in? container
  container.include? self
end

=> nil

puts "good" if a.in? %w(word1 word2 word3 whatever)

good

fwiw, sometimes in cases like this, i start off with a... case,

case a
when "word1", "word2","word3"
  puts "good"
end

then just sprinkle w more cases, and beautify as i go...

···

From: Greg Lazarev [mailto:russianbandit@gmail.com]

6

You forgot the anchors. Your regexp will also match "fooword1bar" which was not intended by OP. Also, IIRC it is more efficient to switch sides, i.e.

puts 'good' if /\Aword[1-3]\z/ =~ a

For _large_ sets of words which do not follow a simple pattern a Set may be more efficient

TEST = %w{word1 word2 word3 plus many more words}.to_set.freeze

puts 'good' if TEST.include? a

Kind regards

  robert

···

On 11.11.2008 01:56, Brian Adkins wrote:

Greg Lazarev <russianbandit@gmail.com> writes:

I'm wondering if there's a better way to do this in ruby:

if a == "word1" || a == "word2" or || a == "word3"
  puts "good"
end

I realize that you probably want a more general solution (which others
have already provided); however, if 'a' *does* follow a pattern:

puts 'good' if a =~ /word[1-3]/

or

puts 'good' if a =~ /word\d+/

7

Robert Klemme wrote:

puts 'good' if a =~ /word[1-3]/

or

puts 'good' if a =~ /word\d+/

You forgot the anchors. Your regexp will also match "fooword1bar" which
was not intended by OP.

(...)

Kind regards

  robert

Is this a bug?

("word1".."word3").each{|w| puts w}
=> word1
=> word2
=> word3
puts "good" if ("word1".."word3").include?("word1bar")
=> good

If so, what am I supposed to do?

Siep

···

On 11.11.2008 01:56, Brian Adkins wrote:

--
Posted via http://www.ruby-forum.com/\.

8

Robert Klemme <shortcutter@googlemail.com> writes:

···

On 11.11.2008 01:56, Brian Adkins wrote:

puts 'good' if a =~ /word[1-3]/

or

puts 'good' if a =~ /word\d+/

You forgot the anchors. Your regexp will also match "fooword1bar"
which was not intended by OP. Also, IIRC it is more efficient to
switch sides, i.e.

Interesting - I wouldn't think there would be a difference, but I just
benchmarked it and it appears that putting the pattern on the left
gives a 1.2% speed boost.

--
Brian Adkins
http://www.lojic.com/

9

# puts "good" if ("word1".."word3").include?("word1bar")
# => good
# If so, what am I supposed to do?

ruby range is just being friendly, so do not rely too much :wink:
to be explicit, convert it to array then

puts "good" if ("word1".."word3").to_a.include?("word1bar")

=> nil

···

From: Siep Korteling [mailto:s.korteling@gmail.com]