Tutorial by Examples: b

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...

Dynamic binding, also referred as method overriding is an example of run time polymorphism that occurs when multiple classes contain different implementations of the same method, but the object that the method will be called on is unknown until run time. This is useful if a certain condition dicta...

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...

Records are an extension of sum algebraic data type that allow fields to be named: data StandardType = StandardType String Int Bool --standard way to create a sum type data RecordType = RecordType { -- the same sum type with record syntax aString :: String , aNumber :: Int , isTrue :...

Access ModifierVisibilityInheritancePrivateClass onlyCan't be inheritedNo modifier / PackageIn packageAvailable if subclass in packageProtectedIn packageAvailable in subclassPublicEverywhereAvailable in subclass There was once a private protected (both keywords at once) modifier that could be appli...

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...

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. ...

beacon = CLBeaconRegion(proximityUUID: <#NSUUID#>, major: <#CLBeaconMajorValue#>, identifier: <#String#>) // listening to all beacons with given UUID and major value beacon = CLBeaconRegion(proximityUUID: <##NSUUID#>, major: <##CLBeaconMajorValue#>, minor: <##C...

Use to push commits made on your local branch to a remote repository. The git push command takes two arguments: A remote name, for example, origin A branch name, for example, master For example: git push <REMOTENAME> <BRANCHNAME> As an example, you usually run git push orig...

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...

To install packages directly from GitHub use the devtools package: library(devtools) install_github("authorName/repositoryName") To install ggplot2 from github: devtools::install_github("tidyverse/ggplot2") The above command will install the version of ggplot2 that corre...

We have to create a view which will have a image prefix to a text. text could be of variable length.We have to achieve a result where in Image + text is always in center of a parent view. Step 1: First create a single view project and name it something of your choice and open the story board fist...

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_...

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 ...

If you want to extend a class as-if you are a static function, for example for class Something add static looking function fromString, this can only work if the class has a companion object and that the extension function has been declared upon the companion object: class Something { compani...

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...