1. Code & Supply #StarterSeries
Why?
Job Growth
Software development jobs will grow 32% through
2020.
Pays well
$93,350 median salary (2012)
Fun
Creative outlet

2. Other reasons? This presentation
Me

3. Professional Rails Dev - 5 years
Professional Software - 7 years
@justinxreese @codeandsupply @builderworksco
Starting out
Code ProgramEditorEnvironment Results Code ProgramEditorEnvironment Results
Code ProgramEditorEnvironment Results Code ProgramEditorEnvironment Results

4. Code ProgramEditorEnvironment Results Code ProgramEditorEnvironment Results
Code ProgramEditorEnvironment Results Code ProgramEditorEnvironment Results
What is a
program?
Basically: A file that can be
executed
More typically: a collection of
files that can be executed
How does
a program
run?
Think of it like “opening a
file with Ruby”

5. Code ProgramEditorEnvironment Results
Different Kinds of Programming
- Web
- Ruby on Rails, JavaScript, Python
- Native
- iOS (Objective-C, Swift), Android, OSX
- Systems
- Go, C, Rust
Different Programming Languages Different types of languages
- Functional
- Object oriented
- Concurrent
- Markup
Ruby
Why this class uses Ruby
- Object Oriented
- Typically used for web
- English-like syntax
- I know it well

6. Ruby on Rails?
Ruby != Rails
Ruby != Rails
!= means “these things are not equal”
Ruby == Ruby
Ruby == Ruby
== means “these things are equal”

7. 1 == 1 1 == 1
1 == 1
3 == 3
1 == 1
3 == 3
1 == 1
3 == 3
4 == 5
1 == 1
3 == 3
4 == 5

8. 1 == 1 true
3 == 3 true
4 == 5 false
You just learned booleans!
1 == 1 true
3 == 3 true
4 == 5 false
You already knew booleans!
1 == 1 true
3 == 3 true
4 == 5 false
Why not “=”?
Assignment
Because = is used to
assign things
x = 5
eyes = 2
fingers = 10
Assignment
Variables because the
values can change
x = 5
eyes = 2
fingers = 10
horrible_accident
fingers = 9

9. Using variables
Can be used in
calculations
my_eyes = 2
your_eyes = 2
my_eyes + your_eyes
=> 4
More operators*
* Don’t try to learn all of these today
Other operators
What other things can
you do with variables?
Arithmetic
pies = 3
people = 2
pies + people # 5
pies - people # 1
pies * people # 6
pies / people # 1 (???)
pies % people # 1
pies ** people # 9
Other operators
What other things can
you do with variables?
Comparison
pies = 3
people = 2
pies == people # false
pies != people # true
pies > people # true
pies < people # false
pies >= people # true
pies <= people # false
pies ⇔ people # 1
pies === people # false
Other operators
What other things can
you do with variables?
Logic
pies = 3
people = 2
pies && people
pies and people
pies || people
pies or people
!pies and !people
not pies and not people
Back to variables

10. Variables aren’t just numbers
Give it a name my_eyes = 2
my_name = “Justin”
Using variables
What if I try this? my_eyes = 2
my_name = “Justin”
my_eyes + my_name
Using variables
What if I try this? my_eyes = 2
my_name = “Justin”
my_eyes + my_name
=> Error
Why does it break?
Variables are
incompatible types
Data structure is
different
my_eyes = 2 # Integer
my_name = “Justin” # String
my_eyes + my_name
=> Error
Common types
- Symbols
- Hashes
- Arrays
- Strings
- Integers
- Floats
- Booleans
symbol = :symbol
hash = {a: 1, b: 2}
array = [1,2,3]
string = “Hello”
integer = 1
float = 1.5
boolean = true

11. Types we’ll use tonight
- Arrays
- Strings
- Integers
- Booleans
array = [1,2,3]
string = “Hello”
integer = 1
boolean = true
Array
Good for holding lists classmates = [‘Sandy’, ‘Josh’,
‘Amy’, ‘Alfred’]
dice_numbers = [1,2,3,4,5,6]
d20_numbers = dice_numbers +
[7,8,9,10,11,12,13,14,15,16,17,18,19
,20]
Control
Iteration
Doing something for
each item in a list
classmates = [‘Sandy’, ‘Josh’,
‘Amy’, ‘Alfred’]
classmates.each do |classmate|
puts classmate
end
Conditions
If/Else
Do something that
depends on the result
of something else
classmates = [‘Sandy’, ‘Josh’,
‘Amy’, ‘Alfred’]
classmates.each do |classmate|
if classmate == ‘Sandy’
puts classmate
else
puts “who?”
end
end

12. Code organization
Methods
Pieces of functionality
grouped together
def say_hello
puts “hello”
end
Modules
Group together like
methods
module Greetings
def say_hello
puts “hello”
end
def say_hello_french
puts “bonjour”
end
end
Classes
Group methods related
to a type of object
class Person
attr_accessor :first_name, :
last_name
def full_name
first_name + last_name
end
end
You can program
Concepts you’ve learned
- Assignment
- Data structures
- Iteration
- Conditions

13. Use of concepts
These basic concepts can get you through most
any problem you’ll have in programming
Advanced topics will help you get better
- Design patterns
- Object oriented programming
- Architecture
- Frameworks
- Libraries
- Abstraction
- More...
Time to code
Ruby
For this class we’ll
use runnable
IRB
Interactive shell

14. Creating and running a program
my_program.rb
“open with” ruby
Becoming a good developer
Mini-presentation time!
Learn the
language well
Before you dive into Rails
- Learn Ruby well
- Be able to spot the boundaries between Ruby the
language and Rails the framework
Learn the ecosystem
- Learn the tools around Ruby
- Many libraries (Gems) to do specific tasks
Learn best practices
- Version control
- test driven development
- clean code (DRY)

15. Community involvement
- Code & Supply events
- lectures
- build nights
Continuing education
- Codecademy, Treehouse - Like today, but no instructor
- Ruby Koans
Participate/Give back
- Ask questions. answer anything you can
- IRC - #ruby #codeandsupply
- StackOverflow
- Don’t be afraid of being wrong
Don’t be afraid of
being wrong
Continuing Education