CODEWITHSUNDEEP
ruby
CrunchyBanana
CrunchyBanana

Reputation: 11

Convert array string objects into hashes?

I have an array:

a = ["us.production => 1", "us.stats => 1", "us.stats.total_active => 1", "us.stats.inactive => 0"]

How can I modify it into a hash object? e.g.:

h = {"us.production" => 1, "us.stats" => 1, "us.stats.total_active" => 1, "us.stats.inactive" => 0}

Thank you,

Upvotes: 0

Views: 59

Answers (3)

ray
ray

Reputation: 5552

If pattern you are having is proper and constant, you can try following,

h = a.map { |x| x.split(' => ') }.to_h
# => {"us.production"=>"1", "us.stats"=>"1", "us.stats.total_active"=>"1", "us.stats.inactive"=>"0"}

Instead it is better to use split(/\s*=>\s*/) instead of split(' => ')

Upvotes: 2

Cary Swoveland
Cary Swoveland

Reputation: 110755

The other answers to date are incorrect because they leave the values as strings, whereas the spec is that they be integers. That can be easily corrected. One way is to change s.split(/\s*=>\s*/) in @mrzasa's answer to k,v = s.split(/\s*=>\s*/); [k,v.to_i]. Another way is to tack .transform_values(&:to_i) to the ends of the expressions given in those answers. I expect the authors of those answers either didn't notice that integers were required or intended to leave it as an exercise for the OP to do the (rather uninteresting) conversion.

To make a single pass through the array and avoid the creation of a temporary array and local variables (other than block variables), I suggest using Enumerable#each_with_object (rather than map and to_h), and use regular expressions to extract both keys and values (rather than using String#split):

a = ["us.production   => 1", "us.stats=>1", "us.stats.total_active => 1"]

a.each_with_object({}) { |s,h| h[s[/.*[^ ](?= *=>)/]] = s[/\d+\z/].to_i }
  #=> {"us.production"=>1, "us.stats"=>1, "us.stats.total_active"=>1}

The first regular expression reads, "match zero or more characters (.*) followed by a character that is not a space ([^ ]), provided that is followed by zero or more spaces (*) followed by the string "=>". (?= *=>) is a positive lookahead.

The second regular expression reads, "match one or more digits (\d+) at the end of the string (the anchor \z). If that string could represent a negative integer, change that regex to /-?\d+\z/ (? makes the minus sign optional).

Upvotes: 1

mrzasa
mrzasa

Reputation: 23347

You can split every string with String#split and then convert an array of pairs into a hash with Array#to_h:

a = ["us.production => 1", "us.stats => 1", "us.stats.total_active => 1", "us.stats.inactive => 0"]
pairs = a.map{|s| s.split(/\s*=>\s*/)}
# => [["us.production", "1"], ["us.stats", "1"], ["us.stats.total_active", "1"], ["us.stats.inactive", "0"]]
pairs.to_h
# => {"us.production"=>"1", "us.stats"=>"1", "us.stats.total_active"=>"1", "us.stats.inactive"=>"0"}

/\s*=>\s*/ is a regular expression that matches first any number of whitespaces with \s*, then => then again any nuber of whitespaces. As it's a String#split delimiter, this part of string won't be present in a string pair.

Upvotes: 1

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