Tutorial by Examples: s

Common Lisp does not have interfaces in the sense that some languages (e.g., Java) do, and there is less need for that type of interface given that Common Lisp supports multiple inheritance and generic functions. However, the same type of patterns can be realized easily using mixin classes. This e...

Let's say we have a table team_person as below: +======+===========+ | team | person | +======+===========+ | A | John | +------+-----------+ | B | Smith | +------+-----------+ | A | Walter | +------+-----------+ | A | Louis | +------+-----------+ | C | ...

Determine if an object has (or contains) a key. If the key to search for is expressed as a path (with dot notation) it will traverse nested object structures to determine if the key exists. var obj = { a: 2, b: 3, c: { dd:40, ee:{ fff:500 } } }; var res1 = _.ha...

To install the software: After the download completes, run the installer. For Windows, the installer executable file has the .exe extension. Double-click the installer file to run it. For Linux platforms, the installer file has the .sh extension. For these platforms, you need to make ...

To install the software: After the download completes, run the installer. The installer file has the .dmg extension. On the panel that opens double-click the package icon. The package has the .pkg extension. The installation wizard starts. Click Continue when the "This package will run a p...

To run the software: After the download of the platform-independent ZIP file completes, extract it to any folder on your system. Run the executable file located in the netbeans/bin directory. Accept the License Agreement. Click Next. The NetBeans IDE installation starts. Note: If a compatib...

PHP 5.4+ comes with a built-in development server. It can be used to run applications without having to install a production HTTP server such as nginx or Apache. The built-in server is only designed to be used for development and testing purposes. It can be started by using the -S flag: php -S &lt...

R contains a Date class, which is created with as.Date(), which takes a string or vector of strings, and if the date is not in ISO 8601 date format YYYY-MM-DD, a formatting string of strptime-style tokens. as.Date('2016-08-01') # in ISO format, so does not require formatting string ## [1] &quot...

Sometimes you will create classes that won't be used in their own right, rather only be extended inside other rule sets. This means that the compiled CSS file will be larger than it needs to be. Placeholder selectors solve this problem. Placeholder selectors are similar to class selectors, but th...

Subqueries come in several flavors, and they have different optimization potential. First, note that subqueries can be either "correlated" or "uncorrelated". Correlated means that they depend on some value from outside the subquery. This generally implies that the subquery mus...

Create a testing class in the src/test/scala directory, in a file named HelloWorldSpec.scala. Put this inside the file: import org.scalatest.{FlatSpec, Matchers} class HelloWorldSpec extends FlatSpec with Matchers { "Hello World" should "not be an empty String" in { ...

Detailed instructions on getting cloudkit set up or installed.

// app.module.ts import { NgModule } from '@angular/core'; import { BrowserModule } from '@angular/platform-browser'; import { HttpModule } from '@angular/http'; import { MyRootComponent } from './app.component'; @NgModule({ declarations: [MyRootComponent], imports: [BrowserModule, Ht...

import { platformBrowserDynamic } from '@angular/platform-browser-dynamic'; import { MyModule } from './app.module'; platformBrowserDynamic().bootstrapModule( MyModule ); In this example, MyModule is the module containing your root component. By bootstrapping MyModule your Angul...

This example has two parts - some boilerplate steps for adding Castle Windsor to your WCF service, and then a simple, concrete example to show how we configure and use Windsor's container. That makes the example a little bit long. If you already understand using a DI container then you likely only ...

Helper yii\helpers\Url provides a set of static methods for managing URLs. This helper may used in views/controllers code. URL to a route: echo Url::to(['post/index']); URL to a route with parameters: echo Url::to(['post/view', 'id' => 100]); anchored URL: echo Url::to(['post/view', 'id...

/** * Checks if a resource exists by sending a HEAD-Request. * @param url The url of a resource which has to be checked. * @return true if the response code is 200 OK. */ public static final boolean checkIfResourceExists(URL url) throws IOException { HttpURLConnection conn = (HttpURLCo...

Let's say you're working on an app called MyTasks, and you want to allow inbound URLs to create a new task with a title and a body. The URL you're designing might look something like this: mytasks://create?title=hello&body=world (Of course, the text and body parameters are used to populate our...

Sometimes we need to perform basic operations like hide/show view based on single value, for that single variable we cannot create model or it is not good practice to create model for that. DataBinding supports basic datatypes to perform those oprations. <layout xmlns:android="http://schema...

First Initialize FirebaseDatabase: FirebaseDatabase database = FirebaseDatabase.getInstance(); Write to your database: // Write a message to the database FirebaseDatabase database = FirebaseDatabase.getInstance(); DatabaseReference myRef = database.getReference("message"); myRef....