Tutorial by Examples: er

A class can have members. Instance variables can be declared with/without type annotations, and optionally initialized. Uninitialised members have the value of null, unless set to another value by the constructor. class Foo { var member1; int member2; String member3 = "Hello world!&q...

Setup monitoring beacons func initiateRegion(ref:BeaconHandler){ let uuid: NSUUID = NSUUID(UUIDString: "<UUID>") let beacon = CLBeaconRegion(proximityUUID: uuid, identifier: "") locationManager?.requestAlwaysAuthorization() //cllocation manager obj. ...

Sometimes two arrays of the same length need to be iterated together, for example: $people = ['Tim', 'Tony', 'Turanga']; $foods = ['chicken', 'beef', 'slurm']; array_map is the simplest way to accomplish this: array_map(function($person, $food) { return "$person likes $food\n"; ...

The installer requires PHP 5.4 or higher. If you still use the legacy PHP 5.3 version, you cannot use the Symfony Installer. Read the Creating Symfony Applications without the Installer section to learn how to proceed. - source: http://symfony.com/doc/current/book/installation.html

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_...

Collections are one of the most commonly used data structures in software engineering. A Collection is just a group of objects. A collection can be a List, an array, a map, a tree or anything. So, a collection should provide some way to access its elements without exposing its internal structure. ...

Given any value of type Int or Long to render a human readable string: fun Long.humanReadable(): String { if (this <= 0) return "0" val units = arrayOf("B", "KB", "MB", "GB", "TB", "EB") val digitGroups = (Mat...

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 ...

With this declaration: fun Temporal.toIsoString(): String = DateTimeFormatter.ISO_INSTANT.format(this) You can now simply: val dateAsString = someInstant.toIsoString()

Kotlin allows us to provide implementations for a predefined set of operators with fixed symbolic representation (like + or *) and fixed precedence. To implement an operator, we provide a member function or an extension function with a fixed name, for the corresponding type. Functions that overload ...

Taken from jQuery.ajax API web site: $.ajax({ method: "POST", url: "some.php", data: { name: "John", location: "Boston" }, success: function(msg) { alert("Data Saved: " + msg); }, error: ...

For instance, two tables are given, T1 id x y 8 42 1.9 9 30 1.9 T2 id signal 8 55 8 56 8 59 9 57 9 58 9 60 The goal is to get the new table T3: id x y s1 s2 s3 8 42 1.9 55 ...

Let's say you have an object like this: var myObject = { name: 'Peter' } Later in your code, you try to access myObject.name and you get George instead of Peter. You start wondering who changed it and where exactly it was changed. There is a way to place a debugger (or something else) on e...

Consider this simple example: import QtQuick 2.7 import QtQuick.Controls 2.0 ApplicationWindow { visible: true width: 400 height: 640 Rectangle{ id: rect anchors.centerIn: parent height: 100 width: parent.width color: "blue...

Sample Data: CREATE TABLE table_name ( id, list ) AS SELECT 1, 'a,b,c,d' FROM DUAL UNION ALL -- Multiple items in the list SELECT 2, 'e' FROM DUAL UNION ALL -- Single item in the list SELECT 3, NULL FROM DUAL UNION ALL -- NULL list SELECT 4, 'f,,g' FROM DUAL; -- NULL item...

Sample Data: CREATE TABLE table_name ( id, list ) AS SELECT 1, 'a,b,c,d' FROM DUAL UNION ALL -- Multiple items in the list SELECT 2, 'e' FROM DUAL UNION ALL -- Single item in the list SELECT 3, NULL FROM DUAL UNION ALL -- NULL list SELECT 4, 'f,,g' FROM DUAL; -- NULL item...

You can implement the swipe-to-dismiss and drag-and-drop features with the RecyclerView without using 3rd party libraries. Just use the ItemTouchHelper class included in the RecyclerView support library. Instantiate the ItemTouchHelper with the SimpleCallback callback and depending on which functi...

using System.Net; ... string serverResponse; try { // Call a method that performs an HTTP request (per the above examples). serverResponse = PerformHttpRequest(); } catch (WebException ex) { if (ex.Status == WebExceptionStatus.ProtocolError) { HttpWebResponse...

Common table expressions support extracting portions of larger queries. For example: WITH sales AS ( SELECT orders.ordered_at, orders.user_id, SUM(orders.amount) AS total FROM orders GROUP BY orders.ordered_at, orders.user_id ) SELECT sales.ordered_at, sales.total,...

This example generates random values between 0 and 2147483647. Random rnd = new Random(); int randomNumber = rnd.Next();