Tutorial by Examples: nd

Enum classes can also declare members (i.e. properties and functions). A semicolon (;) must be placed between the last enum object and the first member declaration. If a member is abstract, the enum objects must implement it. enum class Color { RED { override val rgb: Int = 0xFF0000 ...

The size of a canvas is the area it occupies on the page and is defined by the CSS width and height properties. canvas { width : 1000px; height : 1000px; } The canvas resolution defines the number of pixels it contains. The resolution is set by setting the canvas element width and heigh...

This example will show you how to create a simple animation using the canvas and the 2D context. It is assumed you know how to create and add a canvas to the DOM and obtain the context // this example assumes ctx and canvas have been created const textToDisplay = "This is an example that uses...

There are many situation where you want to draw an image that is rotated, scaled, and translated. The rotation should occur around the center of the image. This is the quickest way to do so on the 2D canvas. These functions a well suited to 2D games where the expectation is to render a few hundred e...

Pyinstaller is a normal python package. It can be installed using pip: pip install pyinstaller Installation in Windows For Windows, pywin32 or pypiwin32 is a prerequisite. The latter is installed automatically when pyinstaller is installed using pip. Installation in Mac OS X PyInstaller works...

Think about a situation where we need to callback a function with arguments. std::function used with std::bind gives a very powerful design construct as shown below. class A { public: std::function<void(int, const std::string&)> m_CbFunc = nullptr; void foo() { ...

The $_FILES["FILE_NAME"]['error'] (where "FILE_NAME" is the value of the name attribute of the file input, present in your form) might contain one of the following values: UPLOAD_ERR_OK - There is no error, the file uploaded with success. UPLOAD_ERR_INI_SIZE - The uploaded fi...

Redirect any naked domain to www.[your_domain].tld: # Start Apache Rewriting engine RewriteEngine On # Make sure you're not already using www subdomain # and that the host string is not empty RewriteCond %{HTTP_HOST} !^$ RewriteCond %{HTTP_HOST} !^www\. # We check for http/https connection ...

Bash indirection permits to get the value of a variable whose name is contained in another variable. Variables example: $ red="the color red" $ green="the color green" $ color=red $ echo "${!color}" the color red $ color=green $ echo "${!color}" the ...

1. URLByDeletingPathExtension: If the receiver represents the root path, this property contains a copy of the original URL. If the URL has multiple path extensions, only the last one is removed. 2. URLByAppendingPathExtension: Returns a new URL made by appending a path extension to the original U...

To create a JAR containing all of its dependencies, it is possible to use the built-in descriptor format jar-with-dependencies. The following example configures an execution of the Assembly Plugin bound to the package phase, using this built-in descriptor and declaring a main class of com.example: ...

Shortest match: $ a='I am a string' $ echo "${a%a*}" I am Longest match: $ echo "${a%%a*}" I

Commands have one input (STDIN) and two kinds of outputs, standard output (STDOUT) and standard error (STDERR). For example: STDIN root@server~# read Type some text here Standard input is used to provide input to a program. (Here we're using the read builtin to read a line from STDIN.) STDO...

{ echo "contents of home directory" ls ~ } > output.txt

import pandas as pd df = pd.DataFrame({'gender': ["male", "female","female"], 'id': [1, 2, 3] }) >>> df gender id 0 male 1 1 female 2 2 female 3 To encode the male to 0 and female to 1: df.loc[df["gender&quot...

Suppose we have an interface: interface IPerson { name: string; age: number; breath(): void; } And we want to create more specific interface that has the same properties of the person, we can do it using the extends keyword: interface IManager extends IPerson { managerId:...

The ng-show directive shows or hides the HTML element based on if the expression passed to it is true or false. If the value of the expression is falsy then it will hide. If it is truthy then it will show. The ng-hide directive is similar. However, if the value is falsy it will show the HTML elemen...

Create an interface decorated with a ServiceContract attribute and member functions decorated with the OperationContract attribute. namespace Service { [ServiceContract] interface IExample { [OperationContract] string Echo(string s); } } Create a concrete...

$(window).load() was deprecated in jQuery version 1.8 (and completely removed from jQuery 3.0) and as such should not be used anymore. The reasons for the deprecation are noted on the jQuery page about this event Caveats of the load event when used with images A common challenge developers attem...

An explicit intent is used for starting an activity or service within the same application package. In this case the name of the intended class is explicitly mentioned: Intent intent = new Intent(this, MyComponent.class); startActivity(intent); However, an implicit intent is sent across the sys...