SpriteKit functionality can be implemented in a subclass of SKScene. For example, a game may implement the main game functionality within an SKScene subclass called GameScene.
In Swift:
import SpriteKit
class GameScene: SKScene {
override func didMoveToView(view: SKView) {
/* Co...
An SKScene has a scaleMode parameter that defines how it will change its size to fit within the SKView it is presented into the SKView if it is not the same size and/or shape.
There are four options for scaleMode:
AspectFit: the scene is scaled (but not stretched) until it fits within the view. ...
You can place an SKCameraNode into an SKScene to define which part of the scene is shown in the SKView. Think of the SKScene as a 2D world with a camera floating above it: the SKView will show what the camera 'sees'.
E.g. the camera could be attached to the main character's sprite to follow the act...
Chaining assignments as part of a var declaration will create global variables unintentionally.
For example:
(function foo() {
var a = b = 0;
})()
console.log('a: ' + a);
console.log('b: ' + b);
Will result in:
Uncaught ReferenceError: a is not defined
'b: 0'
In the above examp...
class SomeClass {
public function __invoke($param1, $param2) {
// put your code here
}
}
$instance = new SomeClass();
$instance('First', 'Second'); // call the __invoke() method
An object with an __invoke method can be used exactly as any other function.
The __invoke meth...
Mapping
Applying a function to all elements of an array :
array_map('strtoupper', $array);
Be aware that this is the only method of the list where the callback comes first.
Reducing (or folding)
Reducing an array to a single value :
$sum = array_reduce($numbers, function ($carry, $number) {
...
The following function can be used to get some basic information about the current browser and return it in JSON format.
function getBrowserInfo() {
var
json = "[{",
/* The array containing the browser info */
info = [
navigator.userA...
After your service worker is registered, the browser will try to install & later activate the service worker.
Install event listener
this.addEventListener('install', function(event) {
console.log('installed');
});
Caching
One can use this install event returned to cache the assets ne...
MySQL offers a number of different numeric types. These can be broken down into
GroupTypesInteger TypesINTEGER, INT, SMALLINT, TINYINT, MEDIUMINT, BIGINTFixed Point TypesDECIMAL, NUMERICFloating Point TypesFLOAT, DOUBLEBit Value TypeBIT
MySQL's DECIMAL and NUMERIC types store exact numeric data values. It is recommended to use these types to preserve exact precision, such as for money.
Decimal
These values are stored in binary format. In a column declaration, the precision and scale should be specified
Precision represents the n...
FLOAT and DOUBLE represent approximate data types.
TypeStoragePrecisionRangeFLOAT4 bytes23 significant bits / ~7 decimal digits10^+/-38DOUBLE8 bytes53 significant bits / ~16 decimal digits10^+/-308
REAL is a synonym for FLOAT. DOUBLE PRECISION is a synonym for DOUBLE.
Although MySQL also permits...
WebSocket provides a duplex/bidirectional communication protocol over a single TCP connection.
the client opens a connection to a server that is listening for a WebSocket request
a client connects to a server using a URI.
A server may listen to requests from multiple clients.
Server Endpoint...
Character escaping is what allows certain characters (reserved by the regex engine for manipulating searches) to be literally searched for and found in the input string. Escaping depends on context, therefore this example does not cover string or delimiter escaping.
Backslashes
Saying that backsla...
The easiest and quickest way to encode a Haskell data type to JSON with Aeson is using generics.
{-# LANGUAGE DeriveGeneric #-}
import GHC.Generics
import Data.Text
import Data.Aeson
import Data.ByteString.Lazy
First let us create a data type Person:
data Person = Person { firstName :...
Detailed instructions on excel-formula(s).
There are many formulas that you can choose from. They are divided up into 7 different categories and are on the FORMULAS tab in Excel. The categories are:
Financial
Logical
Text
Date & Time
Lookup & Reference
Math & trig
More Function...
You should not save props into state. It is considered an anti-pattern. For example:
export default class MyComponent extends React.Component {
constructor() {
super();
this.state = {
url: ''
}
this.onChange = this.onChange.bind(this);
...
Sometimes you doesn't want to simply replace or remove the string. Sometimes you want to extract and process matches. Here an example of how you manipulate matches.
What is a match ? When a compatible substring is found for the entire regex in the string, the exec command produce a match. A match i...
Because Regular Expressions can do a lot, it is tempting to use them for the simplest operations. But using a regex engine has a cost in memory and processor usage: you need to compile the expression, store the automaton in memory, initialize it and then feed it with the string to run it.
And there...
If you want to extract something from a webpage (or any representation/programming language), a regex is the wrong tool for the task. You should instead use your language's libraries to achieve the task.
If you want to read HTML, or XML, or JSON, just use the library that parses it properly and ser...
UserType belongs to many Users <-> Users have one UserType
One way navigation property with required
public class UserType
{
public int UserTypeId {get; set;}
}
public class User
{
public int UserId {get; set;}
public int UserTypeId {get; set;}
public virtual UserType...
