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public class CustomFormat : IFormatProvider, ICustomFormatter { public string Format(string format, object arg, IFormatProvider formatProvider) { if (!this.Equals(formatProvider)) { return null; } if (format == "Reverse") ...

div { font-size: 7px; border: 3px dotted pink; background-color: yellow; color: purple; } body.mystyle > div.myotherstyle { font-size: 11px; background-color: green; } #elmnt1 { font-size: 24px; border-color: red; } .mystyle .myotherstyle { ...

7 Object spreading is just syntactic sugar for Object.assign({}, obj1, ..., objn); It is done with the ... operator: let obj = { a: 1 }; let obj2 = { ...obj, b: 2, c: 3 }; console.log(obj2); // { a: 1, b: 2, c: 3 }; As Object.assign it does shallow merging, not deep merging. let obj3 = ...

In order to create a new Android HTTP Client HttpURLConnection, call openConnection() on a URL instance. Since openConnection() returns a URLConnection, you need to explicitly cast the returned value. URL url = new URL("http://example.com"); HttpURLConnection connection = (HttpURLConnect...

URL url = new URL("http://example.com"); HttpURLConnection connection = (HttpURLConnection) url.openConnection(); try { BufferedReader br = new BufferedReader(new InputStreamReader(connection.getInputStream())); // read the input stream // in this case, I simply read t...

URL url = new URL("http://example.com"); HttpURLConnection connection = (HttpURLConnection) url.openConnection(); try { BufferedReader br = new BufferedReader(new InputStreamReader(connection.getInputStream())); // use a string builder to bufferize the response body //...

SQL injection is a kind of attack that allows a malicious user to modify the SQL query, adding unwanted commands to it. For example, the following code is vulnerable: // Do not use this vulnerable code! $sql = 'SELECT name, email, user_level FROM users WHERE userID = ' . $_GET['user']; $conn->...

A nice example of a parameterized type is the Option type. It is essentially just the following definition (with several more methods defined on the type): sealed abstract class Option[+A] { def isEmpty: Boolean def get: A final def fold[B](ifEmpty: => B)(f: A => B): B = if (i...

The return type of a method can depend on the type of the parameter. In this example, x is the parameter, A is the type of x, which is known as the type parameter. def f[A](x: A): A = x f(1) // 1 f("two") // "two" f[Float](3) // 3.0F Scala will use type infe...

// Create a block with an asynchronous action var block = new ActionBlock<string>(async hostName => { IPAddress[] ipAddresses = await Dns.GetHostAddressesAsync(hostName); Console.WriteLine(ipAddresses[0]); }); block.Post("google.com"); // Post items to the block's ...

var httpClient = new HttpClient(); // Create a block the accepts a uri and returns its contents as a string var downloaderBlock = new TransformBlock<string, string>( async uri => await httpClient.GetStringAsync(uri)); // Create a block that accepts the content and prints it to t...

If you have several objects of monadic types, we can achieve combinations of the values using a 'for comprehension': for { x <- Option(1) y <- Option("b") z <- List(3, 4) } { // Now we can use the x, y, z variables println(x, y, z) x // the last expre...

There are two Dockerfile directives to specify what command to run by default in built images. If you only specify CMD then docker will run that command using the default ENTRYPOINT, which is /bin/sh -c. You can override either or both the entrypoint and/or the command when you start up the built im...

In Go, an error is represented by any value that can describe itself as string. Any type that implement the built-in error interface is an error. // The error interface is represented by a single // Error() method, that returns a string representation of the error type error interface { Erro...

Any Chrome extension starts as an unpacked extension: a folder containing the extension's files. One file it must contain is manifest.json, which describes the basic properties of the extension. Many of the properties in that file are optional, but here is an absolute minimum manifest.json file: ...

The getAll() method retrieves all values from the preferences. We can use it, for instance, to log the current content of the SharedPreferences: private static final String PREFS_FILE = "MyPrefs"; public static void logSharedPreferences(final Context context) { SharedPreferences s...

Yii2 can be installed in two ways. They are Installing via Composer Installing from an Archive File Installing via Composer Installing Composer If you do not already have Composer installed, you may do so by following the instructions at getcomposer.org. On Linux and Mac OS X, you'll run th...

Boilerplate code example override func viewDidLoad() { super.viewDidLoad() let myView = UIView() myView.backgroundColor = UIColor.blueColor() myView.translatesAutoresizingMaskIntoConstraints = false view.addSubview(myView) // Add constraints code here // ... ...

CREATE TABLE Person ( PersonID INT UNSIGNED NOT NULL, LastName VARCHAR(66) NOT NULL, FirstName VARCHAR(66), Address VARCHAR(255), City VARCHAR(66), PRIMARY KEY (PersonID) ); A primary key is a NOT NULL single or a multi-column identifier whic...

Detailed instructions on getting pandas set up or installed can be found here in the official documentation. Installing pandas with Anaconda Installing pandas and the rest of the NumPy and SciPy stack can be a little difficult for inexperienced users. The simplest way to install not only pandas, ...