Tutorial by Examples: st

Partial credit to this SO answer. List Concatenation aggregates a column or expression by combining the values into a single string for each group. A string to delimit each value (either blank or a comma when omitted) and the order of the values in the result can be specified. While it is not part ...

Sometimes you want to add an element to the beginning of an array without modifying any of the current elements (order) within the array. Whenever this is the case, you can use array_unshift(). array_unshift() prepends passed elements to the front of the array. Note that the list of elements is ...

There are a number of different ways to install the AWS CLI on your machine, depending on what operating system and environment you are using: On Microsoft Windows – use the MSI installer. On Linux, OS X, or Unix – use pip (a package manager for Python software) or install manually with the bundle...

The preferred way of describing dependencies is by using constructor injection which follows Explicit Dependencies Principle: ITestService.cs public interface ITestService { int GenerateRandom(); } TestService.cs public class TestService : ITestService { public int GenerateRando...

Builtin container comes with a set of builtin features : Lifetime control public void ConfigureServices(IServiceCollection services) { // ... services.AddTransient<ITestService, TestService>(); // or services.AddScoped<ITestService, TestSer...

App::uses('YourModel', 'Model'); $model_1 = new YourModel(array('ds' => 'default')); $model_2 = new YourModel(array('ds' => 'database2'));

For Addition "4" + 2 # Gives "42" 4 + "2" # Gives 6 1,2,3 + "Hello" # Gives 1,2,3,"Hello" "Hello" + 1,2,3 # Gives "Hello1 2 3" For Multiplication "3" * 2 # Gives "33" 2 * "3&quot...

Swift let viewController = UIViewController() Objective-C UIViewController *viewController = [UIViewController new];

Sometimes two arrays of the same length need to be iterated together, for example: $people = ['Tim', 'Tony', 'Turanga']; $foods = ['chicken', 'beef', 'slurm']; array_map is the simplest way to accomplish this: array_map(function($person, $food) { return "$person likes $food\n"; ...

To install packages directly from GitHub use the devtools package: library(devtools) install_github("authorName/repositoryName") To install ggplot2 from github: devtools::install_github("tidyverse/ggplot2") The above command will install the version of ggplot2 that corre...

You must add php to your path environment variable. Follow theses steps : Windows 7 : Right-click on a My Computer icon Click Properties Click Advanced system settings from the left nav Click Advanced tab Click Environment Variables button In the System Variables section, select Path (case-...

The installer requires PHP 5.4 or higher. If you still use the legacy PHP 5.3 version, you cannot use the Symfony Installer. Read the Creating Symfony Applications without the Installer section to learn how to proceed. - source: http://symfony.com/doc/current/book/installation.html

Open your command console and execute the following commands: $ sudo curl -LsS https://symfony.com/installer -o /usr/local/bin/symfony $ sudo chmod a+x /usr/local/bin/symfony

Given any value of type Int or Long to render a human readable string: fun Long.humanReadable(): String { if (this <= 0) return "0" val units = arrayOf("B", "KB", "MB", "GB", "TB", "EB") val digitGroups = (Mat...

In Kotlin you could write code like: val x: Path = Paths.get("dirName").apply { if (Files.notExists(this)) throw IllegalStateException("The important file does not exist") } But the use of apply is not that clear as to your intent. Sometimes it is clearer to create a ...

With this declaration: fun Temporal.toIsoString(): String = DateTimeFormatter.ISO_INSTANT.format(this) You can now simply: val dateAsString = someInstant.toIsoString()

If you want to extend a class as-if you are a static function, for example for class Something add static looking function fromString, this can only work if the class has a companion object and that the extension function has been declared upon the companion object: class Something { compani...

NumPy is available in the default repositories of most popular Linux distributions and can be installed in the same way that packages in a Linux distribution are usually installed. Some Linux distributions have different NumPy packages for Python 2.x and Python 3.x. In Ubuntu and Debian, install nu...

Custom routing provides specialized need of routing to handle specific incoming requests. In order to defining custom routes, keep in mind that the order of routes that you add to the route table is important. public static void RegisterRoutes(RouteCollection routes) { routes.IgnoreRoute(&qu...

Let's say you have an object like this: var myObject = { name: 'Peter' } Later in your code, you try to access myObject.name and you get George instead of Peter. You start wondering who changed it and where exactly it was changed. There is a way to place a debugger (or something else) on e...