Code & Supply #StarterSeries

Why?

Job Growth

Software development jobs will grow 32% through 2020.

Pays well

$93,350 median salary (2012)

Fun

Creative outlet

Other reasons? This presentation

Me

Professional Rails Dev - 5 yearsProfessional Software - 7 years

@justinxreese @codeandsupply @builderworksco

Starting out

Code ProgramEditorEnvironment Results Code ProgramEditorEnvironment Results

Code ProgramEditorEnvironment Results Code ProgramEditorEnvironment Results

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”

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

Ruby on Rails?

Ruby != Rails

Ruby != Rails

!= means “these things are not equal”

Ruby == Ruby

Ruby == Ruby

== means “these things are equal”

1 == 1 1 == 1

1 == 13 == 3

1 == 13 == 3

1 == 13 == 34 == 5

1 == 13 == 34 == 5

1 == 1 true3 == 3 true4 == 5 false

You just learned booleans!1 == 1 true3 == 3 true4 == 5 false

You already knew booleans!1 == 1 true3 == 3 true4 == 5 false Why not “=”?

AssignmentBecause = is used to assign things

x = 5

eyes = 2

fingers = 10

AssignmentVariables because the values can change

x = 5

eyes = 2

fingers = 10

horrible_accident

fingers = 9

Using variablesCan be used in calculations

my_eyes = 2

your_eyes = 2

my_eyes + your_eyes

=> 4More operators*

* Don’t try to learn all of these today

Other operatorsWhat other things canyou 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 operatorsWhat other things canyou 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 operatorsWhat other things canyou 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

Variables aren’t just numbersGive it a name my_eyes = 2

my_name = “Justin”

Using variablesWhat if I try this? my_eyes = 2

my_name = “Justin”

my_eyes + my_name

Using variablesWhat 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

Types we’ll use tonight- Arrays- Strings- Integers- Booleans

array = [1,2,3]

string = “Hello”

integer = 1

boolean = true

ArrayGood 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

IterationDoing something foreach item in a list

classmates = [‘Sandy’, ‘Josh’, ‘Amy’, ‘Alfred’]

classmates.each do |classmate|

puts classmate

end

Conditions

If/ElseDo something that depends on the resultof something else

classmates = [‘Sandy’, ‘Josh’, ‘Amy’, ‘Alfred’]

classmates.each do |classmate|

if classmate == ‘Sandy’

puts classmate

else

puts “who?”

end

end

Code organization

MethodsPieces of functionality grouped together

def say_hello

puts “hello”

end

ModulesGroup together like methods

module Greetings

def say_hello

puts “hello”

end

def say_hello_french

puts “bonjour”

end

end

ClassesGroup methods relatedto 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

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

RubyFor this class we’lluse runnable

IRB

Interactive shell

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)

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 ofbeing wrong

Continuing Education