User:Jarle Pahr/Ruby

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http://www.sapphiresteel.com/The-Book-Of-Ruby

http://rubyinstaller.org/downloads/

Ruby glossary: http://www.codecademy.com/glossary/ruby

Ruby: https://www.ruby-lang.org/en/documentation/

Poignant guide to Ruby: slav.uniqpath.com/poignant-guide/book/chapter-1.html

Ruby documentation: https://www.ruby-lang.org/en/documentation/

Contents

Gems

rest-client

json

Hashes

http://www.ruby-doc.org/core-1.9.3/Hash.html


Examples

Get input:

user_input = gets.chomp

Search for substring in string:

string.include? "substring"


Convert to uppercase:

string.upcase!

Define a class:

class Person:
attr_accessor :id, :first_name, :last_name
end

Create instance of class:

person = Person.new


Get HTTP response:

require 'rest-client'
response = RestClient.get base_url + "/names/", headers=headers

Show JSON content:

JSON.pretty_generate variable


For loop:

for num in 1...10
 puts num
end

"Each" iterator:

object.each { |item| # Do something }

or

object.each do |item| # Do something end

Do loop:

i = 0
loop do
 i += 1
 print "#{i}"
 break if i > 5
 end


Times iterator:

numberoftimes.times{do something}


Split string:

words = text.split(" ")

Hash tables

rocket notation:

hash = { key1 => value1, key2 => value2}

with symbols:


hash = {:symbol1 => value1, :symbol2 => value2}

new symbol notation:

hash = {key1: value1,key2: value2}

select:

good_movies = movie_ratings.select{|k,v| v >3}

Iterate over keys only:

movie_ratings.each_key {|k| puts k}

Delete from hash:

hashtable.delete(key)

Check if an object responds to a method:

object.respond_to?(:methodname)

Shoveling:

[1, 2, 3] << 4

Collect: Applies an expression to all elements in an array.

doubled_fibs = fibs.collect {|num| num *2}

Yield parameter to block:

def double(par)
   yield par
end
double(2) {|x| x=2*x}


Inheritance:

class DerivedClass < BaseClass
 # Some stuff!
end
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