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Showing posts from 2015

Rails 4 WITH NO Database

Sometimes, you may want to create a Rails application without ActiveRecord or a database. There might be situations like, Your application only store data using third party APIs, or storing in to files or might not have any persistent data at all. Since Rails stands for the common case (database backed application), by default it fails to start the server without a database connection.

You can simply build a Rails app without a database:
Comment / Remove any database gems ( mysql, mysql2, sqlite, pg, mongoid, etc..) from your Gemfile and then run bundle.  Open your application.rb. By default, in Rails 4.0 you can see one line which requires all of Rails:
require 'rails/all'This includes ActiveRecord also, and requires a database connection. Instead, you can include the specific parts of Rails that you gonna use.
See below:
require 'action_controller/railtie'require 'action_mailer/railtie'require 'active_model/railtie'require 'sprockets/railtie…

Conference Track Management - Ruby solution

I got to solve this problem as the part of an interview process.
It wont look good if I paste the whole code here.

So just sharing the link to my gitbub account. Conference Track Management

Binary Search implementation in Ruby

def binary_search(array, value, from=0, to=nil)    to = array.count - 1 unless to     mid = (from + to) / 2    if value < array[mid]      return binary_search(array, value, from, mid - 1)    elsif value > array[mid]      return binary_search(array, value, mid + 1, to)    else      return mid    endend
puts binary_search([1,2,3,4,5,7,8,9,10,12,15,16,17,18], 15)

Program to perform divison operation of two numbers without using /, %, and modules operator

def devide(divisor, dividend)
  quotient = 0
  until(dividend < divisor) do
    dividend -= divisor
    quotient += 1
  end
  quotient
end
puts devide(15, 100)

Ruby Count, Length & Size

These methods can be applied on Arrays, Hashes or Objects.  Here I'm just trying to illustrate the difference between count, length and size. Array#length Basically length method returns number of elements in the array.
Example, suppose we have array arr as, arr = [1,2,3,4,5] Calling Array#length method on array will give result as, arr.length => 5 Array#size Array#size is just an alias to the Array#length method. This method executes same as that of Array#length method internally.
Example, arr.size => 5 Array#count It has more functionalities than length or size. This method can be used for getting number of elements based on some condition. Unlike length/size, we can pass block or an argument to count. This can be called in three ways: Array#count => without condition, Returns number of elements in Array Array#count(n) => passing value, Returns number of elements having value n in Array Array#count{|i| i.zero?} => passing block, Returns count based on cond…