Tutorial by Examples: ev

To register your device for push notifications, add the following code to your AppDelegate file in didFinishLaunchingWithOptions method: Swift func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool { // Override point for c...

When a user press F1 on a control or click on Help button of form (?) and then clicks on a control the HelpRequested event will be raised. You can handle this event to provide custom action when user requests help for controls or form. The HelpRequested supports bubble up mechanism. It fires for y...

You can detect when a user Clicked on a HelpButton on title-bar of form by handling HelpButtonClicked. You can let the event continue or cancel it by setting Cancel property of its event args to true. private void Form1_HelpButtonClicked(object sender, CancelEventArgs e) { e.Cancel = true; ...

Below is a recursive code to reverse a string /** * Just a snippet to explain the idea of recursion * **/ public class Reverse { public static void main (String args[]) { String string = "hello world"; System.out.println(reverse(string)); //prints dlrow oll...

SELECT * FROM Cars WHERE status IN ( 'Waiting', 'Working' ) This is semantically equivalent to SELECT * FROM Cars WHERE ( status = 'Waiting' OR status = 'Working' ) i.e. value IN ( <value list> ) is a shorthand for disjunction (logical OR).

Before we start... In terms of application layers your ViewModel is a class containing all the business logic and rules making the app do what it should according to the requirements. It's also important to make it as much independent as possible reducing references to UI, data layer, native featur...

Lazy evaluation means Haskell will evaluate only list items whose values are needed. The basic recursive definition is: f (0) <- 0 f (1) <- 1 f (n) <- f (n-1) + f (n-2) If evaluated directly, it will be very slow. But, imagine we have a list that records all the results, fibs ...

The code below implements a very simple complex number type for which the underlying field is automatically promoted, following the language's type promotion rules, under application of the four basic operators (+, -, *, and /) with a member of a different field (be it another complex<T> or so...

The first thing we need to do it add EventBus to our module's gradle file: dependencies { ... compile 'org.greenrobot:eventbus:3.0.0' ... } Now we need to create a model for our event. It can contain anything we want to pass along. For now we'll just make an empty class. public ...

Queries can be performed in two ways, both of which return an ADO Recordset object which is a collection of returned rows. Note that both of the examples below use the OpenDatabaseConnection function from the Making a connection to a data source example for the purpose of brevity. Remember that the...

You can quickly switch to the previous branch using git checkout -

Dim aList as New List(Of String) aList.Add("Hello, World") aList.Add("Test") Dim output As String = aList(0) output: Hello, World If you do not know the index of the item or only know part of the string then use the Find or FindAll method Dim aList as New List(Of S...

If you have the version tag v2.3 you can display all commits since that tag. gitk v2.3..

In your Storyboard, add a UITableView object on your UIViewController and let it cover the entire view. Setup the UITableviewDataSource and UITableviewDelegate connections. Objective-C In your .h file NSMutableArray *arrayForBool; NSMutableArray *sectionTitleArray; In your .m file - (void)vi...

Event delegation is a process which allow us to avoid adding event listeners to specific nodes; instead, the event listener is added to parent node. This mechanism utilizes the event propagation/bubbling to handle an event at a higher level element/node in the DOM instead of using the element on whi...

Elasticsearch is accessed through a HTTP REST API, typically using the cURL library. The messages between the search server and the client (your or your application) are sent in the form of JSON strings. By default, Elasticsearch runs on port 9200. In the examples below, ?pretty is added to tell El...

Most programming languages, including F#, evaluate computations immediately in accord with a model called Strict Evaluation. However, in Lazy Evaluation, computations are not evaluated until they are needed. F# allows us to use lazy evaluation through both the lazy keyword and sequences. // define ...

F#, like most programming languages, uses Strict Evaluation by default. In Strict Evaluation, computations are executed immediately. In contrast, Lazy Evaluation, defers execution of computations until their results are needed. Moreover, the results of a computation under Lazy Evaluation are cached,...

Type abbreviations allow you to create aliases on existing types to give them a more meaningful senses. // Name is an alias for a string type Name = string // PhoneNumber is an alias for a string type PhoneNumber = string Then you can use the alias just as any other type: // Create a recor...

TRUNCATE tableName; This will delete all the data and reset AUTO_INCREMENT index. It's much faster than DELETE FROM tableName on a huge dataset. It can be very useful during development/testing. When you truncate a table SQL server doesn't delete the data, it drops the table and recreates it, th...