calc_oop.rb

# Calculator class
class Calculator
  def initialize(number1, number2)
    @num1 = number1
    @num2 = number2
  end

  def sum
    @num1 + @num2
  end

  def mult
    @num1 * @num2
  end

  def divide
    @num1 / @num2
  end

  def subtract
    @num1 - @num2
  end

  def all_oper
    arr = []
    arr << sum
    arr << subtract
    arr << mult
    arr << divide
    arr
  end

  def obj_method
    p methods - Calculator.methods
  end

  def self.method
    p Calculator.methods - Class.methods
  end

  def list_oper
    puts methods - self.class.methods
  end

  def check_oper(oper)
    (methods - self.class.methods).include?(oper)
  end
end

begin
  puts 'Enter the first number'
  num1 = gets.chomp
  num1 = Integer(num1)
  puts 'Enter the second number'
  num2 = gets.chomp
  num2 = Integer(num2)
rescue StandardError
  puts 'Invalid input'
  retry
end
obj = Calculator.new(num1, num2)
obj.list_oper
loop do
  puts 'Enter the operation(Type all for all operations and stop to terminate)'
  oper = gets.chomp
  break if oper == 'stop'

  # oper = gets.to_i
  case oper
  when '+'
    puts "Addition: #{obj.sum}"
  when '-'
    puts "Subtraction: #{obj.subtract}"
  when '*'
    puts "Multiplication: #{obj.mult}"
  when '/'
    puts "Division: #{obj.divide}"
  when 'all'
    arr = obj.all_oper
    puts "Addition: #{arr[0]},Subtraction: #{arr[1]},Multiplication: #{arr[2]},Division: #{arr[3]}"
  else
    puts 'Invalid input'
  end
end