How to Convert a Ruby String with Brackets to an Array

How do I convert a Ruby string with brackets to an array?

You'll get what you want with YAML.

But there is a little problem with your string. YAML expects that there's a space behind the comma. So we need this

str = "[[this, is], [a, nested], [array]]"

Code:

require 'yaml'
str = "[[this, is],[a, nested],[array]]"
### transform your string in a valid YAML-String
str.gsub!(/(\,)(\S)/, "\\1 \\2")
YAML::load(str)
# => [["this", "is"], ["a", "nested"], ["array"]]

Ruby Array into string with brackets

I can't say how "ruby-ish" this is, but it's what I would typically do:

puts "['" + array_of_strings.join("','") + "']"

ruby 1.9 how to convert array to string without brackets

Use interpolation instead of concatenation:

reportStr = "In the first quarter we sold #{myArray[3]} #{myArray[0]}(s)."

It's more idiomatic, more efficient, requires less typing and automatically calls to_s for you.

How to convert a string to an array in Ruby

You can use json to convert it to an array.

class T
  require 'json'
  def array_detect(array_string)
    begin
      json = JSON.parse array_string
      if json.is_a? Array
        # is an array
      else
        # not an array
      end
    rescue JSON::ParserError => e
      puts e.message
      # not a valid json string
    end
  end
end

Removing the brackets from an array in Ruby

If you're storing your values as a string such as "123, 123" then there is no point in map &:to_i.

You can use plan_code.split(",").join(", ") or alternatively plan_code.gsub(",", ", ")

Convert a string with brackets to tree, Ruby

Here is a one way you could convert the string to an array.

Code

def arrayify(arr)
  a = split_arr(arr)
  a.map do |h|
    k = h.keys.first
    v = h.values.first
    case v
    when Array then { k => arrayify(v) }
    else { k=>v }
    end
  end
end

def split_arr(arr)
  a = []
  while arr.any?
    word = arr.shift
    if arr.empty? || arr.first != ?(
      a << { word=>nil }
    else
      arr.shift
      close_count = 0
      b = []
      loop do
        token = arr.shift
        case token
        when ?)
          break if close_count == 0
          close_count -= 1
        when ?( then close_count += 1
        end
        b << token
      end
      a << { word=>b }
    end
  end
  a
end

Example

str = "Animals ( Reptiles Birds ( Eagles Pigeons Crows ) ) Foods ( " +
      "Snacks Breakfast ( Pancakes Waffles ) )"

arrayify(str.split)

  #=> [{"Animals"=>[{"Reptiles" =>nil},
  #                 {"Birds"    =>[{"Eagles" =>nil},
  #                                {"Pigeons"=>nil},
  #                                {"Crows"  =>nil}
  #                               ]
  #                 }
  #                ]
  #    },
  #    {"Foods"  =>[{"Snacks"   =>nil},
  #                 {"Breakfast"=>[{"Pancakes"=>nil},
  #                                {"Waffles" =>nil}
  #                               ]
  #                 }
  #                ]
  #    }
  #   ]

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