ruby 기본 입출력

# To start irb console: irb

 

참고: www.garethrees.co.uk/2013/05/04/p-vs-puts-vs-print-in-ruby/

Ruby p vs puts vs print | Gareth Rees: Ruby Programmer and Product Manager from Cardiff, Wales UK

# string 안에서 변수 사용: #{}

first_name = "Mashrur"
last_name = "Hossain"
full_name = "#{first_name}  #{last_name}"
puts  "My first name is #{first_name} and my last name is #{last_name}"

# 각 객체마다 method를 가지고 있음

puts full_name.class
puts full_name.methods

# nil vs empty

# nil : 객체인지?

{}.nil?
{}.empty?

# 입력: gets.chomp

# chomp: 입력 끝에 엔터 무시

# 예제

puts Enter your first name
first_name = gets.chomp
puts "your first name is #{first_name}"

puts Enter your number
number = gets.chomp
puts numer.to_i * 2

 

# 계산기 예제

puts "simple calculator"
20.times{print "-"}
puts
puts "first number"
num_1=gets.chomp
puts "second number"
num_2=gets.chomp
puts "first number + second number = #{num_1.to_f+num_2.to_f}"
puts "first number - second number = #{num_1.to_f-num_2.to_f}"
puts "first number * second number = #{num_1.to_f*num_2.to_f}"
puts "first number / second number = #{num_1.to_f/num_2.to_f}"

# 비교 연산자

# ==

# !=

# >

# <

puts 10.to_int == 10.to_f
puts 10.to_int === 10.to_f
puts 10.eql?(10.0)
# eql compare type