- Ruby Overview
- How Ruby Runs
- Printing
- Variables and Data Types
- Casting and Converting
- Strings
- Numbers
- User Input
- Arrays
- 2 Dimensional Arrays
- Array Methods
- Methods
- If Statements
- Switch Statements
- Dictionaries
- While Loops
- For Loops
- Exception Catching
- Classes and Objects
- Constructors
- Getters and Setters
- Inheritance
Ruby is a general purpose, dynamically typed and reflective, object oriented programming language that was created in the 1990s by Yukihiro Matsumoto. The original intent when creating ruby was to create a true Object Oriented scripting language. Which at the time, in Matsumoto’s optinion, didn’t exist. Ruby was designed to be simple at it’s core, but with an object system that was fully integreated into the language, and not tacked on as a glorified addon.
At the core of ruby is the desire for programmer productivity and fun. Ruby’s core focus is on the programmer not the machine. Therefore ruby attempts to remove as much confusion as possible from the programming process by utilizing a simple, readable syntax and deeply integrated object orientation.
Generally all ruby code is run using an interpreter, although with some implementations of ruby it is possible to compile the code and run it on a virtual machine.
The most popular ruby interpreter is called MRI which stands for Matz’s Ruby Interpreter. Unfortunatly there is no official Ruby Language Reference, so generally the Matz interpreter is seen as the language standard.
Ruby utilizes a garbage collector and it’s syntax is very minimal and simple.
One reason Ruby has become so popular is due to the Ruby on Rails web application framework. Rails is extremely easy to use which is why it’s the framework of choice for tons of large companies like Github, Twitch and Hulu.
puts "Hello"
print "World"
puts "!"=begin
Names are case-sensitive and may begin with:
letters, _
After, may include
letters, numbers, _
Convention says
Start with a lowercase word, then additional words are lowercase separated
by an underscore
ex. my_first_variable
=end
name = "Mike" # Strings
age = 30 # Integer
gpa = 3.5 # Decimal
is_tall = true # Boolean -> True/False
name = "John"
puts "Your name is #{name}"
puts "Your name is " + nameputs 3.14.to_i
puts 3.to_f
puts "3.0".to_s
puts 100 + "50".to_i
puts 100 + "50.99".to_fgreeting = "Hello"
#indexes: 01234
puts greeting.length
puts greeting[0]
puts greeting.include? "llo"
puts greeting.include? "z"
puts greeting[1,3]puts 2 * 3 # Basic Arithmetic: +, -, /, *
puts 2**3 # Exponent
puts 10 % 3 # Modulus Op. : returns remainder of 10/3
puts 1 + 2 * 3 # order of operations
puts 10 / 3.0 # int's and doubles
num = 10
num += 100 # +=, -=, /=, *=
puts num
num = -36.8
puts num.abs()
puts num.round()
# Math class has useful math methods
puts Math.sqrt(144)
puts Math.log(0)puts "Enter your name: "
name = gets #.chomp
puts "Hello #{name}, how are you"
puts "Enter first num: "
num1 = gets.chomp
puts "enter second num: "
num2 = gets.chomp
puts num1.to_f + num2.to_flucky_numbers = [4, 8, "fifteen", 16, 23, 42.0]
# indexes 0 1 2 3 4 5
lucky_numbers[0] = 90
puts lucky_numbers[0]
puts lucky_numbers[1]
puts lucky_numbers[-1]
puts "\n\n"
puts lucky_numbers[2,3]
puts "\n\n"
puts lucky_numbers[2..4]
puts "\n\n"
puts lucky_numbers.lengthnumber_grid = [[],[]]
# numberGrid = [ [1, 2], [3, 4] ]
number_grid[0][0] = 99
puts number_grid[0][0]
puts number_grid[0][1]friends = []
friends.push("Oscar")
friends.push("Angela")
friends.push("Kevin")
# friends.pop
puts friends
puts "\n"
puts friends.reverse
puts "\n"
puts friends.sort
puts "\n"
puts friends.include? "Oscar"def add_numbers(num1, num2=99)
return num1 + num2
end
sum = add_numbers(4, 3)
puts sumis_student = false
is_smart = false
if is_student and is_smart
puts "You are a student"
elsif is_student and !is_smart
puts "You are not a smart student"
else
puts "You are not a student and not smart"
end
# >, <, >=, <=, !=, ==, String.equals()
if 1 > 3
puts "number comparison was true"
end
if "a" > "b"
puts "string comparison was true"
endmy_grade = "A"
case my_grade
when "A"
puts "You Pass"
when "F"
puts "You fail"
else
puts "Invalid grade"
endtest_grades = {
"Andy" => "B+",
:Stanley => "C",
"Ryan" => "A",
3 => 95.2
}
test_grades["Andy"] = "B-"
puts test_grades["Andy"]
puts test_grades[:Stanley]
puts test_grades[3]index = 1
while index <= 5
puts index
index += 1
endfor index in 0..5
puts index
end
5.times do |index|
puts index
end
lucky_nums = [4, 8, 15, 16, 23, 42]
for lucky_num in lucky_nums
puts lucky_num
end
lucky_nums.each do |lucky_num|
puts lucky_num
endbegin
# puts bad_variable
num = 10/0
rescue ZeroDivisionError
puts "Error"
rescue
puts "All other errors"
end
raise "Made Up Exception"class Book
attr_accessor :title, :author
def readBook()
puts "Reading #{self.title} by #{self.author}"
end
end
book1 = Book.new()
book1.title = "Harry Potter"
book1.author = "JK Rowling"
book1.readBook()
puts book1.titleclass Book
attr_accessor :title, :author
def initialize(title, author)
@title = title
@author = author
end
def readBook()
puts "Reading #{self.title} by #{@author}"
end
end
book1 = Book.new("Harry Potter", "JK Rowling")
# book1.title = "Half-Blood Prince"
puts book1.titleclass Book
attr_accessor :title, :author
def initialize(title, author)
self.title = title
@author = author
end
def title=(title)
puts "Set"
@title = title
end
def title
puts "Get"
return @title
end
end
book1 = Book.new("Harry Potter", "JK Rowling")
puts book1.titleclass Chef
attr_accessor :name, :age
def initialize(name, age)
@name = name
@age = age
end
def make_chicken()
puts "The chef makes chicken"
end
def make_salad()
puts "The chef makes salad"
end
def make_special_dish()
puts "The chef makes a special dish"
end
end
class ItalianChef < Chef
attr_accessor :country_of_origin
def initialize(name, age, country_of_origin)
@country_of_origin = country_of_origin
super(name, age)
end
def make_pasta()
puts "The chef makes pasta"
end
def make_special_dish()
puts "The chef makes chicken parm"
end
end
my_chef = Chef.new()
my_chef.make_chicken()
my_italian_chef = ItalianChef.new()
my_italian_chef.make_chicken()