Tutorial by Examples: class

Suppose we have a JSON string： ["first","second","third"] We can parse this JSON string into a String array : Gson gson = new Gson(); String jsonArray = "[\"first\",\"second\",\"third\"]"; String[] strings = gson.fromJson(j...

If you want to create an instance of an inner nested class you need to provide a class object of the enclosing class as an extra parameter with Class#getDeclaredConstructor. public class Enclosing{ public class Nested{ public Nested(String a){ System.out.println("Constru...

If you want your application to support a plug-in system, for example to load plug-ins from assemblies located in plugins folder: interface IPlugin { string PluginDescription { get; } void DoWork(); } This class would be located in a separate dll class HelloPlugin : IPlugin { ...

Classes have a local scope during definition, but functions inside the class do not use that scope when looking up names. Because lambdas are functions, and comprehensions are implemented using function scope, this can lead to some surprising behavior. a = 'global' class Fred: a = 'class' ...

You can use a class to mimic the switch/case structure. The following is using introspection of a class (using the getattr() function that resolves a string into a bound method on an instance) to resolve the "case" part. Then that introspecting method is aliased to the __call__ method to ...

Classes are vital aspects of OOP. A class is like the "blueprint" of an object. An object has the properties of a class, but the characteristics are not defined within the class itself. As each object can be different, they define their own characteristics. Public Class Person End Class ...

Inherits Specifies the base (or parent) class Public Class Person End Class Public Class Customer Inherits Person End Class 'One line notation Public Class Student : Inherits Person End Class Possible objects: Dim p As New Person Dim c As New Customer Dim s As New Student ...

Me uses the current object instance. MyClass uses the memberdefinition in the class where the member is called Class Person Public Overridable Sub DoSomething() Console.WriteLine("Person") End Sub Public Sub useMe() Me.DoSomething() End Sub ...

There are two ways to get singleton class of an object singleton_class method. Reopening singleton class of an object and returning self. object.singleton_class singleton_class = class << object self end

Singleton classes share their instance/class variables with their object. class Example @@foo = :example end def Example.foo class_variable_get :@@foo end Example.foo #=> :example class Example def initialize @foo = 1 end def foo @foo end end e = Ex...

A class is also allowed to have static members, which can be either variables or functions. These are considered to be in the class' scope, but aren't treated as normal members; they have static storage duration (they exist from the start of the program to the end), aren't tied to a particular inst...

Suppose we have a json ： { "total_count": 132, "page_size": 2, "page_index": 1, "twitter_posts": [ { "created_on": 1465935152, "tweet_id": 210462857140252672, "tweet": "Along with our ne...

Sometimes it's useful to be able to extend a class with new functions. For example let's suppose that a string should be converted to a camel case string. So we need to tell TypeScript, that String contains a function called toCamelCase, which returns a string. interface String { toCamelCase()...

Overall the easiest way to work with JSON is to have a case class mapping directly to the JSON (same fields name, equivalent types, etc.). case class Person( name: String, age: Int, hobbies: Seq[String], pet: Pet ) case class Pet( name: String, `type`: String ) // these...

The practice of replacing an object with a test double that verifies expectations, for instance asserting that a method has been called, is referred to as mocking. Lets assume we have SomeService to test. class SomeService { private $repository; public function __construct(Repository $r...

One of the most common obstacles using classes is finding the proper approach to handle private states. There are 4 common solutions for handling private states: Using Symbols Symbols are new primitive type introduced on in ES2015, as defined at MDN A symbol is a unique and immutable data typ...

A Property procedure is a series of statement that retrieves or modifies a custom property on a module. There are three types of property accessors: A Get procedure that returns the value of a property. A Let procedure that assigns a (non-Object) value to an object. A Set procedure that assign...

Any public Sub, Function, or Property inside a class module can be called by preceding the call with an object reference: Object.Procedure In a DateRange class, a Sub could be used to add a number of days to the end date: Public Sub AddDays(ByVal NoDays As Integer) mEndDate = mEndDate + No...

This is an example of a package-info.java file that binds an XML namespace to a serializable Java class. This should be placed in the same package as the Java classes that should be serialized using the namespace. /** * A package containing serializable classes. */ @XmlSchema ( xmlns = ...

SpriteKit functionality can be implemented in a subclass of SKScene. For example, a game may implement the main game functionality within an SKScene subclass called GameScene. In Swift: import SpriteKit class GameScene: SKScene { override func didMoveToView(view: SKView) { /* Co...