rishiip

<h1><center>Rishi Pithadiya</center></h1>

rishiip

Originally published in June 2008

When hiring Ruby on Rails programmers, knowing the right questions to ask during an interview was a real challenge for me at first. In 30 minutes or less, it's difficult to get a solid read on a candidate's skill set without looking at code they've previously written. And in the corporate/enterprise world, I often don't have access to their previous work.

To ensure we hired competent ruby developers at my last job, I created a list of 15 ruby questions -- a ruby measuring stick if you will -- to select the cream of the crop that walked through our doors.

What to expect

Candidates will typically give you a range of responses based on their experience and personality. So it's up to you to decide the correctness of their answer.

rishiip

What's a Hash and why is it important?

A Hash is a collection of key-value pairs. To add, fetch, modify, and delete a value from a Hash, you refer to it with a unique key.

While an Array is indexed by Integers only, a Hash is keyed by any object -- Strings, Integers, etc.

In other programming languages, a Hash might be known as an 'associative array', 'dictionary', or 'HashMap'.

What does a Hash look like?

rishiip

class Api::RegistrationsController < Api::BaseController
  
  respond_to :json
  def create

    user = User.new(params[:user])
    if user.save
      render :json=> user.as_json(:auth_token=>user.authentication_token, :email=>user.email), :status=>201
      return
    else

rishiip

Create the partition:

sgdisk --zap-all /dev/sda
cgdisk /dev/sda
mkfs.ext4 /dev/sda1
mount /dev/sda1 /mnt

Edit the mirror list to bring the preferred mirror to the top:

rishiip

require 'webrick'
 
Port = 3000
Directory = Dir::pwd

WEBrick::HTTPServer.new(
	Port: Port,
	DocumentRoot: Directory
).start

rishiip

# nil? can be used on any Ruby object. It returns true only if the object is nil.
nil.nil?   # => true 
[].nil?    # => false 
{}.nil?    # => false
"".nil?    # => false
" ".nil?   # => false
true.nil?  # => false

# empty? can be used on some Ruby objects including Arrays, Hashes and Strings. It returns true only if the object's length is zero.
nil.empty?   # NoMethodError: undefined method `empty?' for nil:NilClass

rishiip

# RSpec allows us to test private methods of a model.

for example, 

class User
  def is_active?
    true
  end
  private :is_active?
end

rishiip

def get_array_max(one_dim_array)
  one_dim_array.inject([0, 0]) do |(max_so_far, max_up_to_here), x|
    new_max_up_to_here = [max_up_to_here + x, 0].max
    new_max_so_far = [max_so_far, new_max_up_to_here].max
    [new_max_so_far, new_max_up_to_here]
  end.first
end

sample = [-2, 1, -3, 4, -1, 2, 1, -5, 4]
p get_array_max(sample)

rishiip

Save below code to `bson.rb` file within `config/initializers` directory and restart the server

module BSON
  class ObjectId
    def as_json(*args)
      to_s
    end
  end
end