Tutorial by Examples: r

Code $categories = get_the_category(); foreach( $categories as $category ) { echo $category->name . '<br />'; } Output All names of categories of the current page, one on each line.

Code $categories = get_the_category(); foreach( $categories as $category ) { echo $category->term_id . '<br />'; } Output All ids of categories of the current page, one on each line.

Before you can build anything, you are required to make your machine ready for building. For this you need to install a lot of libraries and modules. The most recommended Linux distribution is Ubuntu, so this example will focus on installing everything that is needed on Ubuntu. Installing Java Fir...

Sample Data: CREATE TABLE table_name ( id, list ) AS SELECT 1, 'a,b,c,d' FROM DUAL UNION ALL -- Multiple items in the list SELECT 2, 'e' FROM DUAL UNION ALL -- Single item in the list SELECT 3, NULL FROM DUAL UNION ALL -- NULL list SELECT 4, 'f,,g' FROM DUAL; -- NULL item...

Code the_title( '<h1>', '</h1>' ); Output The title of the current post or page in h1 tags

Code <picture> <source media="(min-width: 600px)" srcset="large_image.jpg"> <source media="(min-width: 450px)" srcset="small_image.jpg"> <img src="default_image.jpg" style="width:auto;"> </picture> ...

add_theme_support( 'post-formats', array( 'formatone', 'formattwo' ) );

add_theme_support( 'post-thumbnails', array( 'post' ) ); The above code only allows post thumnails on all posts. To enable the feature on all post types, do: add_theme_support( 'post-thumbnails' );

In mathematics, especially Set Theory, we have a collection of things which is called set and we name those things as elements. We show a set with its name like A, B, C, ... or explicitly with putting its member on brace notation: {a, b, c, d, e}. Suppose we have an arbitrary element x and a set Z, ...

After you have set a few data to database and have get a structure consisting of several nodes like this; "user" : { "-KdbKcU2ptfYF2xKb5aO" : { "firstName" : "Arthur", "lastName" : "Schopenhauer", "userName&q...

Create enum of custom errors enum RegistrationError: Error { case invalidEmail case invalidPassword case invalidPhoneNumber } Create extension of RegistrationError to handle the Localized description. extension RegistrationError: LocalizedError { public var errorDescription...

See list of http headers. public function someAction(){ // Action's code $response = new Response(); $response->headers->set('Content-Type', 'text/html'); return $response; }

Return JSON formated response: use Symfony\Component\HttpFoundation\JsonResponse; public function someAction(){ // Action's code $data = array( // Array data ); return new JsonResponse($data); }

In this example, User Table will have a column that references the Agency table. CREATE TABLE agencies ( -- first create the agency table id SERIAL PRIMARY KEY, name TEXT NOT NULL ) CREATE TABLE users ( id SERIAL PRIMARY KEY, agency_id NOT NULL INTEGER REFERENCES agencies(id) DEFERR...

In a data declaration, prefixing a type with a bang (!) makes the field a strict field. When the data constructor is applied, those fields will be evaluated to weak head normal form, so the data in the fields is guaranteed to always be in weak head normal form. Strict fields can be used in both rec...

The expiration values of a key can be managed by a user outside of the update commands. Redis allows a user to determine the current time to live (TTL) of a key using the TTL command: TTL key This command will return the TTL of a key in seconds or will return the special values -1 or -2. A -1 ...

wire d = 1'bx; // say from previous block. Will be 1 or 0 in hardware if (d == 1'b) // false in simulation. May be true of false in hardware

The following example demonstrates using Lumen in WAMP / MAMP / LAMP environments. To work with Lumen you need to setup couple of things first. Composer PHPUnit git (not required but strongly recommended) Assuming you have all these three components installed (at least you need composer), f...

Typescript allow to re-export declarations. //Operator.ts interface Operator { eval(a: number, b: number): number; } export default Operator; //Add.ts import Operator from "./Operator"; export class Add implements Operator { eval(a: number, b: number): number { ...

Retrolambda lets you run Java 8 code with lambda expressions, method references and try-with-resources statements on Java 7, 6 or 5. It does this by transforming your Java 8 compiled bytecode so that it can run on an older Java runtime. Backported Language Features: Lambda expressions are back...