Tutorial by Examples: l

Using Output buffer to store contents in a file, useful for reports, invoices etc

<?php ob_start(); ?> <html> <head> <title>Example invoice</title> </head> <body> <h1>Invoice #0000</h1> <h2>Cost: &pound;15,000</h2> ... </body> </html> <?php...

PHP • Output Buffering

Using the multiprocessing module to parallelise tasks

import multiprocessing def fib(n): """computing the Fibonacci in an inefficient way was chosen to slow down the CPU.""" if n <= 2: return 1 else: return fib(n-1)+fib(n-2) p = multiprocessing.Pool() print(p.map(fib,[38,37,3...

Python Language • Parallel computation

Ignore files that have already been committed to a Git repository

If you have already added a file to your Git repository and now want to stop tracking it (so that it won't be present in future commits), you can remove it from the index: git rm --cached <file> This will remove the file from the repository and prevent further changes from being tracked by...

Git • Ignoring Files and Folders

Basics of multithreading

Using the threading module, a new thread of execution may be started by creating a new threading.Thread and assigning it a function to execute: import threading def foo(): print "Hello threading!" my_thread = threading.Thread(target=foo) The target parameter references the fun...

Python Language • Multithreading

Inline Link

The form for a link in markdown is as follows. [Shown Text](Link) For example, This will take you to Example.com is created with [This will take you to Example.com](http://www.example.com)

Markdown • Linking

Recorded (not live) Video Player

twitch • Interactive Embed Video Player

Loading and using a module

A module can be "imported", or otherwise "required" by the require() function. For example, to load the http module that ships with Node.js, the following can be used: const http = require('http'); Aside from modules that are shipped with the runtime, you can also require mod...

Node.js • Exporting and Consuming Modules

Creating a hello-world.js module

Node provides the module.exports interface to expose functions and variables to other files. The most simple way to do so is to export only one object (function or variable), as shown in the first example. hello-world.js module.exports = function(subject) { console.log('Hello ' + subject); }...

Node.js • Exporting and Consuming Modules

Limit and Offset relationship

Considering the following users table: idusername1User12User23User34User45User5 In order to constrain the number of rows in the result set of a SELECT query, the LIMIT clause can be used together with one or two positive integers as arguments (zero included). LIMIT clause with one argument When ...

MySQL • Limit and Offset

Bold

Bold text can be created by surrounding text with either double asterisks or double underscores: **Bolded text** __Also bolded text__ Result: Bolded text Also bolded text

Markdown • Text Formatting

Italic

Italics can be created by surrounding text with either asterisks or with underscores: *Italicized text* _Also italicized_ Result: Italicized text Also italicized

Markdown • Text Formatting

Simple Category

Interface and implementation of a simple category on NSArray, named Filter, with a single method that filters numbers. It is good practice to add a prefix (PF) to the method to ensure we don't overwrite any future NSArray methods. @interface NSArray (PFFilter) - (NSArray *)pf_filterSmaller:(dou...

Objective-C Language • Categories

General Pattern that does most commonly asked about tasks

The following is how to properly use the java.util.Scanner class to interactively read user input from System.in correctly( sometimes referred to as stdin, especially in C, C++ and other languages as well as in Unix and Linux). It idiomatically demonstrates the most common things that are requested ...

Java Language • Scanner

Inline code

Markdown supports adding inline code like this, obtained by wrapping text in backticks: `code here` Alternatively, you can put your inline code between <code> and </code> HTML tags. Consider the following markdown code: `This` is an inline code block! <code>This</code> is...

Markdown • Code

Syntax highlighting (StackExchange)

On StackExchange sites, code snippets may provide optional syntax highlighting. On sites like Stack Overflow the default language is derived from the tags used in the associated question (if applicable). In addition, a code snippet's syntax highlighting language may also be defined by adding an HTML...

Markdown • Code

Numbered lists

1. Lists 2. Can be 3. Numbered Lists Can be Numbered Note that the numbers themselves are ignored: 1. This is the first item 5. This is the fifth item 7. This is the seventh item This is the first item This is the fifth item This is the seventh item However, the firs...

Markdown • Creating Lists

Start with a Muted Player

twitch • Interactive Embed Video Player

Implements Interface

This is an enum that is also a callable function that tests String inputs against precompiled regular expression patterns. import java.util.function.Predicate; import java.util.regex.Pattern; enum RegEx implements Predicate<String> { UPPER("[A-Z]+"), LOWER("[a-z]+&quot...

Java Language • Enums

Making a Payment with a Vaulted Credit Card (Node)

In this example, we'll be looking at how to store a credit card using the PayPal vault, then reference that stored credit card to process a credit card transaction for a user. The reason why we would want to use the vault is so that we don't have to store sensitive credit card information on our ow...

PayPal • Making a Credit Card Payment (Node)

Hello World with C Extension

The following C source file (which we will call hello.c for demonstration purposes) produces an extension module named hello that contains a single function greet(): #include <Python.h> #include <stdio.h> #if PY_MAJOR_VERSION >= 3 #define IS_PY3K #endif static PyObject *hell...

Python Language • Writing extensions