Tutorial by Examples: abs

Before C++17, having pointers with a value of nullptr commonly represented the absence of a value. This is a good solution for large objects that have been dynamically allocated and are already managed by pointers. However, this solution does not work well for small or primitive types such as int, w...

In Python 3, PEP 404 changes the way imports work from Python 2. Implicit relative imports are no longer allowed in packages and from ... import * imports are only allowed in module level code. To achieve Python 3 behavior in Python 2: the absolute imports feature can be enabled with from __futu...

The following design pattern is categorized as a creational pattern. An abstract factory is used to provide an interface for creating families of related objects, without specifying concrete classes and can be used to hide platform specific classes. interface Tool { void use(); } interf...

Disclaimer: the examples presented here are only for the purpose of showing the use of abstract classes and inheritance and may not necessarily be of a practical use. Also, there is no sich thing as polymorphic in MATLAB and therefore the use of abstract classes is limited. This example is to show w...

To create a prefab, drag a game object from the scene hierarchy into the Assets folder or subfolder: The game object name turns blue, indicating it is connected to a prefab. Now this object is a prefab instance, just like an object instance of a class. A prefab can be deleted after instanti...

There are 2 ways of instantiating prefabs: during design time or runtime. Design time instantiation Instantiating prefabs at design time is useful to visually place multiple instances of the same object (e.g. placing trees when designing a level of your game). To visually instantiate a prefab...

The following command executes :command on lines 23 to 56: :23,56command NB: Ranges are inclusive by default.

If classes share common functionality you can group this in a base or abstract class. Abstract classes can contain partial or no implementation at all and allow the derived type to override the base implementation. Abstract classes within VisualBasic.NET must be declared as MustInherit and cannot ...

A common problem when working with Unity is when 2 or more developers are modifying a Unity scene or prefab (*.unity files). Git does not know how to merge them correctly out of the box. Thankfully the Unity team deployed a tool called SmartMerge which makes simple merge automatic. The first thing...

When to use abstract classes: To implement the same or different behaviour among multiple related objects When to use interfaces: to implement a contract by multiple unrelated objects Abstract classes create "is a" relations while interfaces provide "has a" capability. This c...

abstract class Machine { constructor(public manufacturer: string) { } // An abstract class can define methods of it's own, or... summary(): string { return `${this.manufacturer} makes this machine.`; } // Require inheriting classes to implement methods ...

The following abstract defines an EmailAddress type based on the String type which will use a regular expression to validate the passed argument as an e-mail address. If the address isn't valid, an exception will be thrown. abstract EmailAddress(String) { static var ereg = ~/^[\w-\.]{2,}@[\w-\.]...

For efficiency, Prolog code is typically compiled to abstract machine code before it is run. Many different abstract machine architectures and variants have been proposed for efficient execution of Prolog programs. These include: WAM, the Warren Abstract Machine TOAM, an abstract machine used i...

Abstraction is a process of hiding the implementation details and showing only functionality to the user. An abstract class can never be instantiated. If a class is declared as abstract then the sole purpose is for the class to be extended. abstract class Car { abstract void tagLine(); } ...

Return the absolute value of a number SELECT ABS(2); -> 2 SELECT ABS(-46); -> 46 The sign of a number compares it to 0. SignResultExample-1n < 0SELECT SIGN(42); -> 10n = 0SELECT SIGN(0); -> 01n > 0SELECT SIGN(-3); -> -1 SELECT SIGN(-423421); -> -1

Normally Android-SQLiteOpenHelper does not allow fully qualified path names where the database should be stored. So public database files are not possible. You can use the SQLiteOpenHelper with a custom path if you provide a custom ContextClass and if you have write access in the target directory. ...

The Abstract Factory Pattern is a creational design pattern that can be used to define specific instances or classes without having to specify the exact object that is being created. function Car() { this.name = "Car"; this.wheels = 4; } function Truck() { this.name = "Truck"; ...

Abstraction levels help determine when to split things up. Abstraction is achieved by implementing functionality with increasingly detailed code. The entry point of a macro should be a small procedure with a high abstraction level that makes it easy to grasp at a glance what's going on: Public Sub...

Bootstrapping Magento by calling: require_once 'app/Mage.php'; Mage::app(); // Your code This is the simplest way but not really the Magento way because we're not using class that extends Mage_Shell_Abstract - the class which when extended provides us with tools to parse command line arguments...

Magento way File resides in shell/custom.php <?php require_once' abstract.php'; class Stackoverflow_Shell_Custom extends Mage_Shell_Abstract { protected $_argname = array(); public function __construct() { parent::__construct(); // Time limit to infinity ...