Schwad

# Create Fibonnaci Array
a = [1,2]
upto = 4_000_000
while a[-2] + a[-1] < upto
  a << a[-2] + a[-1] 
end
 
# Create sum of even Fibonnaci numbers
sum = 0
a.each { |x| sum+= x if x.even? }

Schwad

def matching_brackets?(arg)
  opener_symbols = ["{", "(", "["]
  closer_symbols = ["}", ")", "]"]
  openers = Hash.new(0)
  closers = Hash.new(0)
  openers['('] = arg.scan(/\(/).length
  openers['['] = arg.scan(/\[/).length
  openers['{'] = arg.scan(/\{/).length
  closers[')'] = arg.scan(/\)/).length
  closers[']'] = arg.scan(/\]/).length

Schwad

Studying for a Tech Interview Sucks, so Here's a Cheat Sheet to Help

This list is meant to be a both a quick guide and reference for further research into these topics. It's basically a summary of that comp sci course you never took or forgot about, so there's no way it can cover everything in depth. It also will be available as a gist on Github for everyone to edit and add to.

Data Structure Basics

###Array ####Definition:

• Stores data elements based on an sequential, most commonly 0 based, index.
• Based on tuples from set theory.

Schwad

Error: Typescript found the following errors:
  /Users/nickschwaderer/Desktop/getting_started/home-library/tmp/broccoli_type_script_compiler-input_base_path-ujnWpQpT.tmp/0/src/app/home-library.component.ts (2, 10): Module '"/Users/nickschwaderer/Desktop/getting_started/home-library/node_modules/@angular/core/index"' has no exported mng 'Http'.
    at BroccoliTypeScriptCompiler._doIncrementalBuild (/Users/nickschwaderer/Desktop/getting_started/home-library/node_modules/angular-cli/lib/broccoli/broccoli-typescript.js:115:19)
    at BroccoliTypeScriptCompiler.build (/Users/nickschwaderer/Desktop/getting_started/home-library/node_modules/angular-cli/lib/broccoli/broccoli-typescript.js:43:10)
    at /Users/nickschwaderer/Desktop/getting_started/home-library/node_modules/angular-cli/node_modules/broccoli-caching-writer/index.js:149:21
    at tryCatch (/Users/nickschwaderer/Desktop/getting_started/home-library/node_modules/angular-cli/node_modules/broccoli-caching-writer/node_modules/rsvp/dist/rsvp.js:538:12)
    at

Schwad

[
["1995-12-21", "0.95"],
["1996-12-25", "1.0-961225"],
["1997-12-25", "1.0-971225"],
["1998-07-17", "1.1c0"],
["1998-07-24", "1.1c1"],
["1998-08-11", "1.1c2"],
["1998-08-27", "1.1c3"],
["1998-09-03", "1.1c4"],
["1998-09-08", "1.1c5"],

Schwad

class String
  
  def nostalgic_case
    upcase.chars.join(" ")
  end
  
end

Schwad

def index
  @books = Book.all
end

#=> Rendering books/index.html.haml within layouts/application

Schwad

def show
  @book = Book.find(params[:id])
  render 'unexpected'
end

#=> Rendering books/unexpected.html.haml within layouts/application

Schwad

def extra_curricular_activity
  @book = Book.find(params[:id])
  render 'show'
  @book.update_column(:title, 'Surprise Surprise')
end

#=> SQL (7.1ms)  UPDATE "books" SET "title" = 'Surprise Surprise' WHERE "books"."id" = $1  [["id", 1]]

Schwad

def double_render_error
  @books = Book.all
  render 'index'
  render 'show'
end

#=> AbstractController::DoubleRenderError - Render and/or redirect were called multiple times in this action. Please note that you may only call render OR redirect, and at most once per action.