CODEWITHSUNDEEP
rubyhash
user3237940
user3237940

Reputation: 11

Ruby hash.key error

I feel like I'm overlooking something here. When I try to use the Hash.key(keytolookfor) method, I get an error.

Is this method deprecated?

pete@Vader:~/tmp$ ruby -v
ruby 2.1.0p0 (2013-12-25 revision 44422) [x86_64-linux]
pete@Vader:~/tmp$ ./hashtest.rb
./hashtest.rb:8: undefined method `key' for {"firstkey"=>"firstvalue", "secondkey"=>"secondvalue"}:Hash (NoMethodError)
pete@Vader:~/tmp$

The script is as follows. 

#!/usr/bin/ruby

testHash = Hash.new
testHash["firstkey"] = "firstvalue"
testHash["secondkey"] = "secondvalue"

if testHash.has_value?("secondvalue")
    keyvalue = testHash.key("secondvalue")
    puts "match found with key #{keyvalue}"
else
    puts "no match found"
end

Upvotes: 1

Views: 257

Answers (2)

Малъ Скрылевъ
Малъ Скрылевъ

Reputation: 16507

Use the heap record for script as follows:

#/usr/bin/env ruby

This picks up the default ruby version specified by the system, rvm, or rbenv. Since Ruby 1.8.7 has no Hash#key, make sure that you're running at least Ruby 1.9.1:

$ /usr/bin/ruby -v
1.9.1p0

Alternatively, use Hash#[] instead:

keyvalue = testHash["secondvalue"]

Upvotes: 0

Victor Moroz
Victor Moroz

Reputation: 9225

My wild guess is that your system ruby /usr/bin/ruby is 1.8.7 which doesn't have Hash#key method. ruby -v most probably shows rvm version which is located in ~/.rvm/..., but first line in your script calls /usr/bin/ruby.

Upvotes: 2

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