Tutorial by Examples: et

if-let, when-let, -let macros

These macros merge control flow and binding. They are an improvement over anaphoric anaphoric macros because they let the developer communicate meaning through naming. As such their use is recommended over their anaphoric counterparts. (if-let (user (get-user user-id)) (show-dashboard user) (...

common-lisp • macros

Getting file information

Check if a path is a directory or a file The is_dir function returns whether the argument is a directory, while is_file returns whether the argument is a file. Use file_exists to check if it is either. $dir = "/this/is/a/directory"; $file = "/this/is/a/file.txt"; echo is_d...

PHP • File handling

Clearing a Set

You can remove all the elements in a set using the .clear() method: mySet.clear();

JavaScript • Set

Getting set length

You can get the number of elements inside the set using the .size property const mySet = new Set([1, 2, 2, 3]); mySet.add(4); mySet.size; // 4 This property, unlike Array.prototype.length, is read-only, which means that you can't change it by assigning something to it: mySet.size = 5; mySet....

JavaScript • Set

Inheritance and methods resolution

To make a class a subclass of another class, use parent pragma: package Point; use strict; ... 1; package Point2D; use strict; use parent qw(Point); ... 1; package Point3D; use strict; use parent qw(Point); ... 1; Perl allows for multiple inheritance: package Point2D; use stri...

Perl Language • Object-oriented Perl

Class and Object Methods

In Perl, the difference between class (static) and object (instance) methods is not so strong as in some other languages, but it still exists. The left operand of the arrow operator -> becomes the first argument of the method to be called. It may be either a string: # the first argument of new ...

Perl Language • Object-oriented Perl

Get previous element

To get the previous element you can use the .prev() method. <ul> <li>Mark</li> <li class="anna">Anna</li> <li>Paul</li> </ul> If you are standing on the "Anna" element and you want to get the previous element, &q...

jQuery • DOM Traversing

Using a base template

base.twig.html <!DOCTYPE html> <html> <head> <title>{{ title | default('Hello World') }}</title> <link rel="stylesheet" type="text/css" href="theme.css"> {% block css %} {% endblock %} &...

twig • Template inheritance

Change the content of an included template

article.twig.html <article> <h1>{{ article.title }}</h1> {% block content %} <p>{{ article.content }}</p> {% endblock %} </article> articles.twig.html {# use default template for article #} {% for article in articles %} {% include &...

twig • Template inheritance

Getting Started

See also the Mercurial Tutorial Creating a Mercurial Repository A Mercurial repository is simply a directory (referred to as the "working directory") containing an .hg directory with metadata about the contents of the repository. This makes Mercurial very lightweight and easy to start us...

mercurial • Getting started with mercurial

DESCRIBE tablename;

DESCRIBE and EXPLAIN are synonyms. DESCRIBE on a tablename returns the definition of the columns. DESCRIBE tablename; Exmple Result: COLUMN_NAME COLUMN_TYPE IS_NULLABLE COLUMN_KEY COLUMN_DEFAULT EXTRA id int(11) NO PRI 0 ...

SQL • EXPLAIN and DESCRIBE

How to configure the build.gradle file

android { ... defaultConfig {...} buildTypes {...} productFlavors { demo { applicationId "com.example.myapp.demo" versionName "1.0-demo" } full { applicationId "com.example.myapp.full"...

android-gradle • Configure Product Flavors

Add a Customizer Section With Basic Settings and their Controls

Panels can have sections, sections can have settings, and settings can have controls. Settings are saved in the database, while the controls for particular settings are only used to display their corresponding setting to the user. This code creates a basic section in the panel from above. Inside a...

WordPress • Customizer Basics (Add Panel, Section, Setting, Control)

Hello World with doGet

Content has been moved back to good 'ol Servlets wiki page

servlets • Getting started with servlets

Attaching a Method to a Button

To add a method to a button, first create an action method: Objective-C -(void) someButtonAction{ NSLog(@"Button is tapped"); } Swift func someButtonAction() { print("Button is tapped") } Now to add this action method to your button, you have to wri...

iOS • UIButton

Use Trigger to manage a "Recycle Bin" for deleted items

CREATE TRIGGER BooksDeleteTrigger ON MyBooksDB.Books AFTER DELETE AS INSERT INTO BooksRecycleBin SELECT * FROM deleted; GO

SQL • Triggers

Installation or Setup

Notepad++ can be installed: From the installer downloaded from the project's web site From Ninite, which would download and automatically install the latest version available: https://ninite.com/notepadplusplus/ Built from sources who are available in the GitHub Repo of this project.

notepad++ • Getting started with notepad++

Installation and Setup

Background ============ WebStorm is lightweight yet powerful Integrated Development Environment (IDE) perfectly equipped for complex client-side development and server-side development, it is cross-platform and works on Windows, Mac OS X, and Linux. WebStorm features advanced support for JavaScri...

webstorm • Getting started with webstorm

Setting a cookie

To set a cookie i.e. to create it and schedule for sending to the browser you need to create new \yii\web\Cookie class instance and add it to response cookies collection: $cookie = new Cookie([ 'name' => 'cookie_monster', 'value' => 'Me want cookie!', 'expire' => time() + 86...

yii2 • Cookies

Session cookie parameters

Session cookies parameters are important both if you have a need to maintain session while getting from one subdomain to another or when, in contrary, you host backend app under /admin URL and want handle session separately. $config = [ // ... 'components' => [ // ... ...

yii2 • Cookies