Tutorial by Examples: v

A common pattern in C# is using bool TryParse(object input, out object value) to safely parse objects. The out var declaration is a simple feature to improve readability. It allows a variable to be declared at the same time that is it passed as an out parameter. A variable declared this way is sco...

Let there be Activity B that can be opened, and can further start more Activities. But, user should not encounter it when navigating back in task activities. The simplest solution is to set the attribute noHistory to true for that <activity> tag in AndroidManifest.xml: <activity a...

demoApp.directive('demoDirective', function () { var directiveDefinitionObject = { multiElement: priority: terminal: scope: {}, bindToController: {}, controller: controllerAs: require: restrict: templateNamespace: template: templateU...

SyncAdapter /** * Define a sync adapter for the app. * <p/> * <p>This class is instantiated in {@link SyncService}, which also binds SyncAdapter to the system. * SyncAdapter should only be initialized in SyncService, never anywhere else. * <p/> * <p>The system ca...

Validating array form input fields is very simple. Suppose you have to validate each name, email and father name in a given array. You could do the following: $validator = \Validator::make($request->all(), [ 'name.*' => 'required', 'email.*' => 'email|unique:users'...

When running from the CLI, PHP exhibits some different behaviours than when run from a web server. These differences should be kept in mind, especially in the case where the same script might be run from both environments. No directory change When running a script from a web server, the current w...

The @var keyword can be used to describe the type and usage of: a class property a local or global variable a class or global constant class Example { /** @var string This is something that stays the same */ const UNCHANGING = "Untouchable"; /** @var string $some_s...

void doSomething(String... strings) { for (String s : strings) { System.out.println(s); } } The three periods after the final parameter's type indicate that the final argument may be passed as an array or as a sequence of arguments. Varargs can be used only in the final argume...

The preferred way of describing dependencies is by using constructor injection which follows Explicit Dependencies Principle: ITestService.cs public interface ITestService { int GenerateRandom(); } TestService.cs public class TestService : ITestService { public int GenerateRando...

Once registered a dependency can be retrieved by adding parameters on the Controller constructor. // ... using System; using Microsoft.Extensions.DependencyInjection; namespace Core.Controllers { public class HomeController : Controller { public HomeController(ITestServic...

Here is how to make a Heads Up Notification for capable devices, and use a Ticker for older devices. // Tapping the Notification will open up MainActivity Intent i = new Intent(this, MainActivity.class); // an action to use later // defined as an app constant: // public static final String ME...

For Addition "4" + 2 # Gives "42" 4 + "2" # Gives 6 1,2,3 + "Hello" # Gives 1,2,3,"Hello" "Hello" + 1,2,3 # Gives "Hello1 2 3" For Multiplication "3" * 2 # Gives "33" 2 * "3&quot...

If a type wishes to have value semantics, and it needs to store objects that are dynamically allocated, then on copy operations, the type will need to allocate new copies of those objects. It must also do this for copy assignment. This kind of copying is called a "deep copy". It effective...

To access pixel values in an OpenCV cv::Mat object, you first have to know the type of your matrix. The most common types are: CV_8UC1 for 8-bit 1-channel grayscale images; CV_32FC1 for 32-bit floating point 1-channel grayscale images; CV_8UC3 for 8-bit 3-channel color images; and CV_32FC3 ...

Swift class FooViewController: UIViewController { override func loadView() { view = FooView() } }

Model using System.ComponentModel.DataAnnotations; public class ViewModel { [Required(ErrorMessage="Name is required")] public string Name { get; set; } [StringLength(14, MinimumLength = 14, ErrorMessage = "Invalid Phone Number")] [Required(ErrorMessag...

Remote Validation used to check whether the content enter in the input control is valid or not by sending an ajax request to server side to check it. Working The RemoteAttribute works by making an AJAX call from the client to a controller action with the value of the field being validated. The con...

In case your project needs to be based on a specific Symfony version, use the optional second argument of the new command: # use the most recent version in any Symfony branch $ symfony new my_project_name 2.8 $ symfony new my_project_name 3.1 # use a specific Symfony version $ symfony new my_...

A common use case for extension methods is to improve an existing API. Here are examples of adding exist, notExists and deleteRecursively to the Java 7+ Path class: fun Path.exists(): Boolean = Files.exists(this) fun Path.notExists(): Boolean = !this.exists() fun Path.deleteRecursively(): Bool...

In Kotlin you could write code like: val x: Path = Paths.get("dirName").apply { if (Files.notExists(this)) throw IllegalStateException("The important file does not exist") } But the use of apply is not that clear as to your intent. Sometimes it is clearer to create a ...