Intro to Programming (1)
1 like563 views
This document provides an overview of a coding class on Ruby and Rails. It discusses: - Why learn to code, mentioning job growth and salaries in software development. - An introduction to Ruby, covering basic concepts like variables, data types, control flow, and code organization techniques. - Tips for becoming a good developer, including learning the language well, understanding related tools and best practices, involvement in the community, and continuing education.
![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](https://image.slidesharecdn.com/734d8301-c075-484d-ab96-3b120a0e2b12-150211183347-conversion-gate02/85/Intro-to-Programming-1-10-320.jpg)
![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](https://image.slidesharecdn.com/734d8301-c075-484d-ab96-3b120a0e2b12-150211183347-conversion-gate02/85/Intro-to-Programming-1-11-320.jpg)
Intro to Programming (1)
- 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