Caroline Artz carolineartz

Ruby Learning Links

Tutorials

#Sorting a Hash I wanted to understand what happened under the hood when something like

hash.sort { |a, b| b[1] <=> a[1] }

is called. If you can't answer, you might want to read.
I'll be as basic as possible (I don't know much anyway...) so it should be understandable.

First let's begin by saying that we will be working on this hash

Testing the speed of different RPN Calculator approaches

The following table shows the speed results of six different approaches to creating a reverse polish notation calculator with Ruby. The code was written by five different incoming Dev Bootcamp students and one instructor.

Approach	Time (ms)
First	119.2
Second	295.6
Third	264.7
Fourth	274.3

Introduction

After working through exercises for learning Ruby as part of preparation for the upcoming Dev Bootcamp (note: no longer exists), we had a friendly discussion about the exercise to implement a Reverse Polish notation calculator. At the end of discussion, one of the staff members, Jesse, posted his solution to students.

The solution is well-designed, clean, and easy to read. However, one line of code caught my eye:

tokenize(array).inject([]) do |stack, token|
      <...>
end.pop

	// Inspired by this post from CSS-Tricks.
	// http://css-tricks.com/snippets/css/less-mixin-for-rem-font-sizing/
	//
	// Plays nice with compass/typography/vertical_rhythm
	// http://compass-style.org/reference/compass/typography/vertical_rhythm/
	//
	// Calculates font size in `rem` (root em).
	//
	// Relative values depends on $base-font-size. Pixle value for font-size depends
	// on $legacy-support-for-ie6 or $legacy-support-for-ie7 or $legacy-support-for-ie8

	<h1>Alert</h1>
	<p>Bootstrap JS</p>
	<div class="alert fade in">
	<button type="button" class="close" data-dismiss="alert">×</button>
	<strong>Holy guacamole!</strong> Best check yo self, you're not looking too good.
	</div>

	<p></p><a ng-click="alert=true">Open Alert (AngularJS)</a></p>
	<div class="alert fade" ng-class="{in:alert}">
	<button type="button" class="close" ng-click="alert=false">×</button>

	# Closures can be done in Ruby using both lambdas and procs.


	# Lambdas with closures:
	# A lambda can be declared so that it is created at runtime but evaluated only when it is called.

	class Person
	def initialize(age)
	@age = age
	end

	def proc_return
	Proc.new { return "proc1"}.call
	return "proc2 I AM HERE!"
	end

	def lambda_return
	lambda { return "lambda1" }.call
	return "lambda2 I AM HERE!"
	end

	class Cookie
	MAX_CHIPS = 100
	end

	class PeanutButterCookie < Cookie
	MAX_CHIPS = 100000
	end

	my_pbc = PeanutButterCookie.new

	http://www.dizzy.co.uk/cheatsheets
	This work is licensed under the Creative Commons
	Attribution-NonCommercial-NoDerivs 2.0 License. To
	view a copy of this license, visit
	http://creativecommons.org/licenses/by-nc-nd/2.0/uk


	########## Shell Commands ##########
	Installation:
	$ gem install capistrano