Write code using Ruby classes and instances

Introduction

I am learning programming. This is the first post. I hope that by writing what I have learned, I will be able to establish myself more. I look forward to working with you.

I will get into the main subject immediately.

Main subject

I took a little time to answer the Ruby problem that came up at a certain programming school, so I will make a note so that I will not forget it. It's a very rudimentary problem, but ... The question and the correct answer are as follows (I'm not happy if the content of the question is the same, so I've changed it a little).

problem


class Article

  def initialize(author, title, content)
    @author = author
    @title = title
    @content = content
  end

end

#Use classes and instances to add to the above code so that you get the following output

The author:Suzuki
title:Nice to meet you
Text:This is the first post

Correct answer (model answer)


class Article

  def initialize(author, title, content) #3rd line
    @author = author
    @title = title
    @content = content
  end

  def author #9th line
    @author
  end

  def title #13th line
    @title
  end

  def content #17th line
    @content
  end

end

article1 = Article.new("Suzuki", "Nice to meet you", "This is the first post") #Line 23

puts "The author: #{article1.author}" #25th line
puts "title: #{article1.title}"
puts "Text: #{article1.content}"

I will explain for myself

First of all, hold down the following

Learn more about each line (Lines 3-7) In the instance variable defined in the initialize method, assign the three values received as arguments, Suzuki,Nice to meet you, and First post, to each instance variable.

(Lines 9-19) Define each instance method to return the value of the instance variable. Of course, for example, if you write @ author instead of ╩╗article1.author on the 25th line without defining these instance methods, Suzuki` will not be output.

(Line 23) Create an instance of the Article class and assign it to the variable article1. At that time, the three values Suzuki, Nice to meet you, and First post are passed as actual arguments to the formal arguments ╩╗author, title, and content`, respectively.

(Lines 25-27) Call the instance method defined in lines 9-19. Instance methods can be called with instance name.method name.

end

I think this article has helped me remember about classes and instances. It was a good opportunity. I will write if something happens again.

Thank you to everyone who has been with us so far.

Recommended Posts

Write code using Ruby classes and instances
[Ruby] Classes and instances
Ruby classes and instances
[Ruby] Creating code using the concept of classes and instances
About Ruby classes and instances
Creating Ruby classes and instances
Writing code with classes and instances
Classes and instances
Memorandum (Ruby: Basic Grammar: Classes and Instances)
java (classes and instances)
About the difference between classes and instances in Ruby
About classes and instances (evolution)
Consideration about classes and instances
[Ruby] Singular methods and singular classes
Ruby methods and classes (basic)
[Ruby] Singular methods and singular classes
Write Ruby methods using C (Part 1)
Organize classes, instances, and instance variables
Write keys and values in Ruby
Classes and instances Java for beginners
Introduce RSpec and write unit test code
[Ruby on Rails] Code check using Rubocop-airbnb
Using Hystrix and Sentinel in code example
[Ruby] Simplify each using map and inject
Java programming (classes and instances, main methods)
Write Ruby methods using C (Numo :: NArray)
Comparison of JavaScript objects and Ruby classes
Write Ruby methods using C ++ (Part 2) Benchmark
Getting Started with Java_Chapter 8_About Instances and Classes
I compared classes and instances with worldly things
Write Selenium Java binding code using Silk WebDriver
Janken program using Ruby and its test (test-unit)
Writing code Ruby
Ruby and Gem
To implement, write the test and then code the process
Java classes and instances to understand in the figure
Symbols and Destructive Ruby
java classes, instances, objects
HashMap and HashSet classes
[Ruby] Big Decimal and DECIMAL
Ruby Learning # 29 Classes & Objects
String literals and instances
Ruby variables and methods
List and happy classes
[For myself] Browser display using JSP files and Servlet classes
Effortlessly handle C ++ classes and functions from Node.js using SWIG
The difference between programming with Ruby classes and programming without it
Write DiscordBot to Spreadsheets Write in Ruby and run with Docker
[Ruby on Rails] Infinite scrolling using gem kaminari and jscroll