Tutorial by Examples: n

A reference to an option &Option<T> cannot be unwrapped if the type T is not copyable. The solution is to change the option to &Option<&T> using as_ref(). Rust forbids transferring of ownership of objects while the objects are borrowed. When the Option itself is borrowed (&a...

Woocommerce is a plugin for WordPress and can be installed like any other WordPress plugin. WooCommerce can only be installed on self hosted installations of WordPress, it cannot be installed onto a site hosted by the wordpress.com service. If you don't have WordPress installed for your website, fo...

There are some ways to break or change a loop's flow. break; will exit the current loop, and will not execute any more lines within that loop. continue; will not execute any more code within the current iteration of the loop, but will remain in the loop. The following loop will execute 101 times ...

localStorage, sessionStorage are JavaScript Objects and you can treat them as such. Instead of using Storage Methods like .getItem(), .setItem(), etc… here's a simpler alternative: // Set localStorage.greet = "Hi!"; // Same as: window.localStorage.setItem("greet", "Hi!&qu...

Type casting is done with either the as operator: var chair:Chair = furniture as Chair; Or by wrapping the value in Type(): var chair:Chair = Chair(furniture); If the cast fails with as, the result of that cast is null. If the cast fails by wrapping in Type(), a TypeError is thrown.

Functions are of the type Function: function example():void { } trace(example is Function); // true They can be referenced by other variables with the type Function: var ref:Function = example; ref(); // ref.call(), ref.apply(), etc. And they can be passed in as arguments for parameters wh...

You can tell the compiler the type of a value by annotating it with :Type: var value:int = 10; // A property "value" of type "int". Function parameters and return types can also be annotated: // This function accepts two ints and returns an int. function sum(a:int, b:int):i...

You can use the is operator to validate whether a value is of a certain type: var sprite:Sprite = new Sprite(); trace(sprite is Sprite); // true trace(sprite is DisplayObject); // true, Sprite inherits DisplayObject trace(sprite is IBitmapDrawable); // true, DisplayObject implements IBitmapDra...

The C++ approach - new and delete In a language like C++, the application program is responsible for managing the memory used by dynamically allocated memory. When an object is created in the C++ heap using the new operator, there needs to be a corresponding use of the delete operator to dispose o...

Sometimes we need to change type from Collection<T?> to Collections<T>. In that case, filterNotNull is our solution. val a: List<Int?> = listOf(1, 2, 3, null) val b: List<Int> = a.filterNotNull()

Detailed instructions on getting monogame set up or installed.

3 You can use rem defined by the font-size of your html tag to style elements by setting their font-size to a value of rem and use em inside the element to create elements that scale with your global font-size. HTML: <input type="button" value="Button"> <input type=...

localStorage.length property returns an integer number indicating the number of elements in the localStorage Example: Set Items localStorage.setItem('StackOverflow', 'Documentation'); localStorage.setItem('font', 'Helvetica'); localStorage.setItem('image', 'sprite.svg'); Get length localSto...

Holy Grail layout is a layout with a fixed height header and footer, and a center with 3 columns. The 3 columns include a fixed width sidenav, a fluid center, and a column for other content like ads (the fluid center appears first in the markup). CSS Flexbox can be used to achieve this with a very s...

This is a minimalist Hello World example that uses only the most basic Android tools. Requirements and assumptions Oracle JDK 1.7 or later Android SDK Tools (just the command line tools) This example assumes Linux. You may have to adjust the syntax for your own platform. Setting up the And...

A simple example on how to read a UTF text file synchronously. import flash.filesystem.File; import flash.filesystem.FileMode; import flash.filesystem.FileStream; //First, get a reference to the file you want to load var myFile:File = File.documentsDirectory.resolvePath("lifestory.txt&...

Declare the AppWidgetProvider class in your application's AndroidManifest.xml file. For example: <receiver android:name="ExampleAppWidgetProvider" > <intent-filter> <action android:name="android.appwidget.action.APPWIDGET_UPDATE" /> </intent-filter&gt...

String concatenation is done simply by writing expressions next to one another without any operator. For example: BEGIN { user = "root" print "Hello "user "!" } will print: Hello root! Note that expressions do not have to be separated by whitespace.

Nine-patch images allow optional definition of the padding lines in the image. The padding lines are the lines on the right and at the bottom. If a View sets the 9-patch image as its background, the padding lines are used to define the space for the View's content (e.g. the text input in an EditTex...

This is MATLAB's long-winded way of saying that it cannot find the function that you're trying to call. There are a number of reasons you could get this error: That function was introduced after your current version of MATLAB The MATLAB online documentation provides a very nice feature which allow...