Ruby Codeacademy Learnings Notes

Linda Solis — Tue, 01 Aug 2023 00:41:59 +0000

Ruby file extension script*.rb*
Commenting two types of comments
Single line comments
start with a #.
Multi line comments start with =begin and end with =end.
put and print commands can be used to display text in the console
Variables: There are four different types of variables in Ruby
Local variables
must begin with a lowercase letter or _. These variables are local to the code block of the method they are declared in.
Instance Variables
Instance variables begin with an @ symbol. Instance variables are variables that belong to an object.
Class Variables
Class variables begin with an @@ sign. Class variables are available across different objects shared by all the descendants of the class. They must be initialized before use.
Global Variables
Global variables begin with an $ symbol. While Class variables are not available across different classes, global variables are. Its scope is global, meaning that it can be accessed from anywhere in the program.
Object Methods
everything in Ruby is an object, are built-in abilities of objects. To access an object’s methods, you need to call it using a . and the method name.
example: # Method to get the string reversed
print var*.reverse*
# ymedacedoc
.length Ruby will return the length of the string (that is, the number of characters—letters, numbers, spaces, and symbols).
.upcase and .downcase
returns a version of the string in all uppercase or all lowercase

example: name = "Jamie"
puts name*.downcase.reverse.upcase*
# EIMAJ
Strings
single quotation marks (‘’) or double quotation marks (“”)
string interpolation
used to insert the result of Ruby code into a string
example: age = 30
print "I am #{age} years old"
# "I am 30 years old"
Get user input in Ruby
using gets.chomp
gets is the method used to retrieve user input.
Ruby automatically adds a new line after each bit of input, so chomp is used to remove that extra line.
example: print "Type your name and press Enter: "
name = gets.chomp
puts "My name is #{name}!"
Modulo
returns the modular value, the remainder, when two numbers are divided.
example: puts 5*.modulo(3)
# Output: **2*
5 is divided by 3 and the remainder is 2
User input Simple Program:
print "What's your first name? "
first_name = gets.chomp
first_name.capitalize!

print "What's your last name? "
last_name = gets.chomp
last_name.capitalize!

puts "Your name is #{first_name} #{last_name}!"

DEV Community: Linda Solis

Ruby Codeacademy Learnings Notes