Tutorial by Examples: bas

Basic usage of a closure

A closure is the PHP equivalent of an anonymous function, eg. a function that does not have a name. Even if that is technically not correct, the behavior of a closure remains the same as a function's, with a few extra features. A closure is nothing but an object of the Closure class which is create...

PHP • Closure

Basic closure binding

As seen previously, a closure is nothing but an instance of the Closure class, and different methods can be invoked on them. One of them is bindTo, which, given a closure, will return a new one that is bound to a given object. For example: <?php $myClosure = function() { echo $this->p...

PHP • Closure

Basic usage

This example creates a simple 1-column repeater that displays a list of numbers, one per repeater item. Markup: <asp:Repeater ID="Repeater1" runat="server"> <ItemTemplate> <%# Container.DataItem.ToString() %> </ItemTemplate> </Repe...

ASP.NET • Repeater

Basic Types

In elm-repl, type a piece of code to get its value and inferred type. Try the following to learn about the various types that exist: > 42 42 : number > 1.987 1.987 : Float > 42 / 2 21 : Float > 42 % 2 0 : Int > 'e' 'e' : Char > "e" "e" : St...

Elm Language • Types, Type Variables, and Type Constructors

Why save user data in the database

Firebase Authentication allows the users of your app to sign-in with social providers or their email+password. But what if you want to store additional information about a user, beyond what Firebase Authentication allows you to specify? Or what if you want to display a list of the users in your app...

firebase • How to use the Firebase Database to keep a list of Firebase Authentication users

Form Tag Helper - Basic example

asp.net-core • Tag Helpers

Nginx installation on Debian and Debian-based distros like Ubuntu

Run command below to install nginx. sudo apt-get install nginx By default, Nginx automatically starts when it is installed. You can access the default Nginx landing page to confirm that the software is running properly by visiting your server's domain name or public IP address in your web browse...

nginx • Getting started with nginx

Basic Union Features

Unions are a specialized struct within which all members occupy overlapping memory. union U { int a; short b; float c; }; U u; //Address of a and b will be equal (void*)&u.a == (void*)&u.b; (void*)&u.a == (void*)&u.c; //Assigning to any union member changes ...

C++ • Unions

Attaching basic events on selections

Often times you will want to have events for your objects. function spanOver(d,i){ var span = d3.select(this); span.classed("spanOver",true); } function spanOut(d,i){ var span = d3.select(this); span.classed("spanOver", false); } var div = d3.select('#divID')...

d3.js • On Events

Basic Element Structure

We got the following very basic element my-element saved as src/my-element.html <link rel="import" href="bower_components/polymer/polymer.html"> <dom-module id="my-element"> <template> <style> /* local styles go here */ ...

polymer • Getting started with polymer

Example showcasing the basic concepts

The following example is an introduction to: Template compilation using underscore Accessing variables in a template Creating a view Rendering a view Showing a view <html> <head> <script src="https://code.jquery.com/jquery-3.1.0.min.js"></script> ...

backbone.js • Getting started with backbone.js

Creating basic deadlocked system

A deadlock occurs when two competing actions wait for the other to finish, and thus neither ever does. In java there is one lock associated with each object. To avoid concurrent modification done by multiple threads on single object we can use synchronized keyword, but everything comes at a cost....

Java Language • Concurrent Programming (Threads)

Basic Update

Updating one row UPDATE customers SET email='[email protected]' WHERE id=1 This query updates the content of email in the customers table to the string [email protected] where the value of id is equal to 1. The old and new contents of the database table are illustrated below on the left an...

MySQL • UPDATE

Basic sample

Unlike other middleware functions error-handling middleware functions have four arguments instead of three: (err, req, res, next). Sample: app.use(function(err, req, res, next) { console.error(err.stack); res.status(500).send('Error found!'); });

express • Error handling

Closure Basics

A Closure is a function taken together with an environment. The function is typically an anonymous function defined inside another function. The environment is the lexical scope of the enclosing function (very basic idea of a lexical scope of a function would be the scope that exists between the fun...

Go • Closures

CREATE Database

A database is created with the following SQL command: CREATE DATABASE myDatabase; This would create an empty database named myDatabase where you can create tables.

SQL • CREATE Database

Basic usage

Load an image, decode it into a bitmap, and display the bitmap in an ImageView (or any other view which implements the ImageAware interface): ImageLoader.getInstance().displayImage(imageUri, imageView); Load an image, decode it into a bitmap, and return the bitmap to a callback: ImageLo...

Android • Universal Image Loader

Basic List Comprehensions

Haskell has list comprehensions, which are a lot like set comprehensions in math and similar implementations in imperative languages such as Python and JavaScript. At their most basic, list comprehensions take the following form. [ x | x <- someList ] For example [ x | x <- [1..4] ] -...

Haskell Language • List Comprehensions

Basics of symbol primitive type

Symbol is a new primitive type in ES6. Symbols are used mainly as property keys, and one of its main characteristics is that they are unique, even if they have the same description. This means they will never have a name clash with any other property key that is a symbol or string. const MY_PROP_KE...

JavaScript • Symbols

Custom colors of logcat message based on message importance

Go to File -> Settings -> Editor -> Colors & Fonts -> Android Logcat Change the colors as you need: Choose the appropriate color:

Android • Android Studio