Tutorial by Examples: w

if let Combines a pattern match and an if statement, and allows for brief non-exhaustive matches to be performed. if let Some(x) = option { do_something(x); } This is equivalent to: match option { Some(x) => do_something(x), _ => {}, } These blocks can also have e...

This example assumes you have already installed Java and Gradle. Use the following project structure: src/ main/ java/ com/ example/ Application.java build.gradle build.gradle is your build script for Gradle build system with the following content: buildscri...

You should implement SFSafariViewControllerDelegate so that your class is notified when the user hits the Done button on the SafariViewController and you can dismiss it as well. First declare your class to implement the protocol. class MyClass: SFSafariViewControllerDelegate { } Implement th...

Don't forget to import the necessary framework first. import SafariServices //Objective-C @import SafariServices; Instantiate a SafariViewController instance. let safariVC = SFSafariViewController(URL: URL(string: "your_url")!) //Objective-C @import SafariServices; NSURL *URL = [...

The function map() from the package maps provides a simple starting point for creating maps with R. A basic world map can be drawn as follows: require(maps) map() The color of the outline can be changed by setting the color parameter, col, to either the character name or hex value of a color...

Run the command below in a shell after installing Ruby. This shows how you can execute simple Ruby programs without creating a Ruby file: ruby -e 'puts "Hello World"' You can also feed a Ruby program to the interpreter's standard input. One way to do that is to use a here document in...

This is the code for a simple console project, that prints "Hello, World!" to STDOUT, and exits with an exit code of 0 [<EntryPoint>] let main argv = printfn "Hello, World!" 0 Example breakdown Line-by-line: [<EntryPoint>] - A .net Attribute that m...

Imports System.IO Dim filename As String = "c:\path\to\file.txt" File.WriteAllText(filename, "Text to write" & vbCrLf)

Dim filename As String = "c:\path\to\file.txt" If System.IO.File.Exists(filename) Then Dim writer As New System.IO.StreamWriter(filename) writer.Write("Text to write" & vbCrLf) 'Add a newline writer.close() End If

using System.Text; using System.IO; string filename = "c:\path\to\file.txt"; //'using' structure allows for proper disposal of stream. using (StreamWriter writer = new StreamWriter(filename")) { writer.WriteLine("Text to Write\n"); }

using System.IO; using System.Text; string filename = "c:\path\to\file.txt"; File.writeAllText(filename, "Text to write\n");

The following program says hello to the user. It takes one positional argument, the name of the user, and can also be told the greeting. import argparse parser = argparse.ArgumentParser() parser.add_argument('name', help='name of user' ) parser.add_argument('-g', '--greeting', ...

docopt turns command-line argument parsing on its head. Instead of parsing the arguments, you just write the usage string for your program, and docopt parses the usage string and uses it to extract the command line arguments. """ Usage: script_name.py [-a] [-b] <path> ...

Swift 3 let stackView = UIStackView() stackView.axis = .horizontal stackView.alignment = .fill // .leading .firstBaseline .center .trailing .lastBaseline stackView.distribution = .fill // .fillEqually .fillProportionally .equalSpacing .equalCentering let label = UILabel() label.text = "...

Swift let stackView = UIStackView() stackView.axis = .Vertical stackView.alignment = .Fill // .Leading .FirstBaseline .Center .Trailing .LastBaseline stackView.distribution = .Fill // .FillEqually .FillProportionally .EqualSpacing .EqualCentering let label = UILabel(frame: CGRectZero) label....

Using the dateutil library as in the previous example on parsing timezone-aware timestamps, it is also possible to parse timestamps with a specified "short" time zone name. For dates formatted with short time zone names or abbreviations, which are generally ambiguous (e.g. CST, which coul...

By default all datetime objects are naive. To make them timezone-aware, you must attach a tzinfo object, which provides the UTC offset and timezone abbreviation as a function of date and time. Fixed Offset Time Zones For time zones that are a fixed offset from UTC, in Python 3.2+, the datetime mod...

Note: you need to install Boot before trying this example out. See the Installation and Setup section if you haven't installed it yet. Boot allows making executable Clojure files using shebang (#!) line. Place the following text into a file of your choice (this example assumes it's in the "cur...

Although it is possible to create a fragment constructor with parameters, Android internally calls the zero-argument constructor when recreating fragments (for example, if they are being restored after being killed for Android's own reasons). For this reason, it is not advisable to rely on a constru...

When trying to select from a table called order like this select * from order the error rises: Error Code: 1064. You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'order' at line 1 Reserved keywords in MySQ...