Scope: Many programming languages implement scope for variables – and they are context sensitive. For example a global scope variable will be over-ridden using local variable definition. You need to implement simple interpreter which tells us current value of a variable, if its not defined then value should be zero, Input will start with ‘[‘ and…

Hoppr_interview_question.rb

puts "Enter your statements separated by a carriage return, The matching braces will terminate the loop"
variables = Hash.new(Hash.new)
opening_brackets = 0
closing_brackets = 0
while true
  variable = nil
  level    = nil
  value    = nil

  input = gets.chomp
  if input.split.join.empty?
    puts "enter your statement"
  else
    if '[' == input
      opening_brackets += 1
      next
    end
    if ']' == input
      if opening_brackets < (closing_brackets+1)
        puts "error in input"
        break
      else
        closing_brackets += 1
        level_to_delete = opening_brackets - closing_brackets + 1
        variables.each do |h,k|
          k.delete(level_to_delete)
        end
        if opening_brackets == closing_brackets
          puts "loop complete"
          break
        else
          next
        end
      end
    end

    input = input.split.join(' ')
    case input.split(' ')[0]
    when 'print'
      if variables.has_key? input.split(' ')[1]
        value_found = false
        (opening_brackets - closing_brackets).downto 1 do |temp|
          unless variables[input.split(' ')[1]][temp].nil?
            puts variables[input.split(' ')[1]][temp]
            value_found = true
            break
          else
            next
          end
        end
        puts 0 unless value_found
      else
        puts 0
      end   
    else
      level = opening_brackets - closing_brackets
      if variables.has_key? input.split(' ')[0]
        if input.split(' ')[1].to_i.to_s == input.split(' ')[1]
          variables["#{input.split(' ')[0]}"].merge! level => (input.split(' ')[1] || "0")
        else
          (opening_brackets - closing_brackets).downto 1 do |temp|
            value = variables[input.split(' ')[1]][temp]
            if value.nil?
              next
            else
              variables["#{input.split(' ')[0]}"].merge! level => value
              break
            end
          end
        end
      else
        value_found = false
        if input.split(' ')[1].to_i.to_s == input.split(' ')[1]
          variables.merge! "#{input.split(' ')[0]}" => {level => (input.split(' ')[1] || "0")}
        else
          (opening_brackets - closing_brackets).downto 1 do |temp|
            value = variables[input.split(' ')[1]][temp]
            if value.nil?
              next
            else
              value_found = true
              variables.merge! "#{input.split(' ')[0]}" => { level => value }
              break
            end
          end
          (variables["#{input.split(' ')[0]}"].merge! level => value ) unless value_found
        end
      end
    end
  end
end