Tutorial by Examples

Strict mode can be applied on entire scripts by placing the statement "use strict"; before any other statements. "use strict"; // strict mode now applies for the rest of the script Strict mode is only enabled in scripts where you define "use strict". You can combin...

Strict mode can also be applied to single functions by prepending the "use strict"; statement at the beginning of the function declaration. function strict() { "use strict"; // strict mode now applies to the rest of this function var innerFunction = function () { ...

NaN ("Not a Number") is a special value defined by the IEEE Standard for Floating-Point Arithmetic, which is used when a non-numeric value is provided but a number is expected (1 * "two"), or when a calculation doesn't have a valid number result (Math.sqrt(-1)). Any equality or ...

Python's str type also features a number of methods that can be used to evaluate the contents of a string. These are str.isalpha, str.isdigit, str.isalnum, str.isspace. Capitalization can be tested with str.isupper, str.islower and str.istitle. str.isalpha str.isalpha takes no arguments and retu...

try { StyledDocument doc = new DefaultStyledDocument(); doc.insertString(0, "This is the beginning text", null); doc.insertString(doc.getLength(), "\nInserting new line at end of doc", null); MutableAttributeSet attrs = new SimpleAttributeSet(); StyleCons...

try { JTextPane pane = new JTextPane(); StyledDocument doc = new DefaultStyledDocument(); doc.insertString(0, "Some text", null); pane.setDocument(doc); //Technically takes any subclass of Document } catch (BadLocationException ex) { //hand...

StyledDocuments generally do not implement clone, and so have to copy them in a different way if that is necessary. try { //Initialization DefaultStyledDocument sourceDoc = new DefaultStyledDocument(); DefaultStyledDocument destDoc = new DefaultStyledDocument(); ...

There are several PHP functions that accept user-defined callback functions as a parameter, such as: call_user_func(), usort() and array_map(). Depending on where the user-defined callback function was defined there are different ways to pass them: Procedural style: function square($number) { ...

// zoo.php class Animal { public function eats($food) { echo "Yum, $food!"; } } $animal = new Animal(); $animal->eats('meat'); PHP knows what Animal is before executing new Animal, because PHP reads source files top-to-bottom. But what if we wanted to create ...

// Animal.php class Animal { public function eats($food) { echo "Yum, $food!"; } } // zoo.php require 'Animal.php'; $animal = new Animal; $animal->eats('slop'); // aquarium.php require 'Animal.php'; $animal = new Animal; $animal->eats('shrimp'); H...

// autoload.php spl_autoload_register(function ($class) { require_once "$class.php"; }); // Animal.php class Animal { public function eats($food) { echo "Yum, $food!"; } } // zoo.php require 'autoload.php'; $animal = new Animal; $animal->e...

// autoload.php spl_autoload_register(function ($class) { require_once "$class.php"; }); // Animal.php class Animal { public function eats($food) { echo "Yum, $food!"; } } // Ruminant.php class Ruminant extends Animal { public function eat...

Static methods and properties are defined on the class/constructor itself, not on instance objects. These are specified in a class definition by using the static keyword. class MyClass { static myStaticMethod() { return 'Hello'; } static get myStaticProperty() { r...

6 Fetch request promises initially return Response objects. These will provide response header information, but they don't directly include the response body, which may not have even loaded yet. Methods on the Response object such as .json() can be used to wait for the response body to load, then p...

An array in go is an ordered collection of same types elements. The basic notation to represent arrays is to use [] with the variable name. Creating a new array looks like var array = [size]Type, replacing size by a number (for example 42 to specify it will be a list of 42 elements), and replacing...

Getters and setters allow you to define custom behaviour for reading and writing a given property on your class. To the user, they appear the same as any typical property. However, internally a custom function you provide is used to determine the value when the property is accessed (the getter), and...

If it's not already done in php.ini, error reporting can be set dynamically and should be set to allow most errors to be shown: Syntax int error_reporting ([ int $level ] ) Examples // should always be used prior to 5.4 error_reporting(E_ALL); // -1 will show every possible error, even whe...

It is possible to create an anonymous struct: data := struct { Number int Text string } { 42, "Hello world!", } Full example: package main import ( "fmt" ) func main() { data := struct {Number int; Text string}{42, "Hello worl...

try/catch try..catch blocks can be used to control the flow of a program where Exceptions may be thrown. They can be caught and handled gracefully rather than letting PHP stop when one is encountered: try { // Do a bunch of things... throw new Exception('My test exception!'); } catch (E...

Usually, you have to use git add or git rm to add changes to the index before you can git commit them. Pass the -a or --all option to automatically add every change (to tracked files) to the index, including removals: git commit -a If you would like to also add a commit message you would do: g...