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If you are given a JSON string : val str = """{ | "name" : "Jsony McJsonface", | "age" : 18, | "hobbies" : [ "Fishing", "Hunting", "Camping" ], | "pet" : { | ...

Self-referential association is used to associate a model with itself. The most frequent example would be, to manage association between a friend and his follower. ex. rails g model friendship user_id:references friend_id:integer now you can associate models like; class User < ActiveRecord:...

This is useful to see if there are any non-printable characters, or non-ASCII characters. e.g. If you have copy-pasted the code from web, you may have quotes like ” instead of standard ". $ cat -v file.txt $ cat -vE file.txt # Useful in detecting trailing spaces. e.g. $ echo '” ' | c...

Because in .NET 3.5 and older you don't have Lazy<T> class you use the following pattern: public class Singleton { private Singleton() // prevents public instantiation { } public static Singleton Instance { get { return Nested.instanc...

To create a new Rails 5 API, open a terminal and run the following command: rails new app_name --api The following file structure will be created: create create README.rdoc create Rakefile create config.ru create .gitignore create Gemfile create app create app/as...

RVM is a great tool to manage your ruby versions and set up your working environment. Assuming you already have RVM installed, to get the latest version of ruby, which is needed for these examples, open a terminal and run: $ rvm get stable $ rvm install ruby --latest Check your ruby version by...

All collection objects contain a map method that takes a Function as an argument, which must take a single argument. This returns an Iterable backed by the collection. When the Iterable is iterated, each step calls the function with a new element of the collection, and the result of the call becomes...

mount is used to mount another application (basically rack application) or rails engines to be used within the current application syntax: mount SomeRackApp, at: "some_route" Now you can access above mounted application using route helper some_rack_app_path or some_rack_app_url. But ...

Step 1: Create the controller, set the delegate, and conform to the protocol //Swift class ImageUploadViewController: UIViewController, UIImagePickerControllerDelegate, UINavigationControllerDelegate { let imagePickerController = UIImagePickerController() override func viewDi...

In this example we want to create a class that will generate and output to console, a random number between a range of two integers which are passed as arguments during the initialization. public class SimpleRangeRandom implements Runnable { private int min; private int max; pr...

When you implement java.io.Serializable interface to make a class serializable, the compiler looks for a static final field named serialVersionUID of type long. If the class doesn't have this field declared explicitly then the compiler will create one such field and assign it with a value which come...

Converting an integer type to the corresponding promoted type is better than converting it to some other integer type. void f(int x); void f(short x); signed char c = 42; f(c); // calls f(int); promotion to int is better than conversion to short short s = 42; f(s); // calls f(short); exact mat...

Download the Atlassian conversion utility here. This utility requires Java, so please ensure that you have the Java Runtime Environment JRE installed on the machine you plan to do the conversion. Use the command java -jar svn-migration-scripts.jar verify to check if your machine is missing any of t...

Installing Tcl 8.6.4 on Windows : The easiest way to get Tcl on a windows machine is to install the ActiveTcl distribution from ActiveState. Navigate to www.activestate.com and follow the links to download the Free Community Edition of ActiveTcl for Windows (choose 32/64 bit version app...

Method stopLoading() stops the current loading process of the webview. Swift webview.stopLoading() Objective-C [webview stopLoading];

Swift webview.reload() Objective-C [webview reload];

There are three kinds of options: boolean options, string options, number options. To check the value of an option, use :set option? to check the value of an option, use :verbose set option? to also see where it was last set. Setting boolean options set booloption " Set boo...

Don't forget the bang to allow Vim to overwrite that function next time you reload the script where the function is defined. Custom functions must start either with an uppercase character (global functions), or with s: (script local functions), or they must be prefixed with the name associated to...

if v:version >= 704 " Do something if Vim is the right version. endif if has('patch666') " Do something if Vim has the right patch-level. endif if has('feature') " Do something if Vim is built with 'feature'. endif See :help has-patch and :help feature-li...

Types & Protocols Type and protocol names should start with an uppercase letter. Example: protocol Collection {} struct String {} class UIView {} struct Int {} enum Color {} Everything else... Variables, constants, functions and enumeration cases should start with a lowercase letter. Exa...