Tutorial by Examples: w

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); }...

<script src= "http://player.twitch.tv/js/embed/v1.js"></script> <div id="{PLAYER_DIV_ID}"></div> <script type="text/javascript"> var options = { width: 854, height: 480, channel: "{CHANNEL}" ...

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...

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...

SELECT 'Hello world!' FROM dual; In Oracle's flavor of SQL, "dual is just a convienence table". It was originally intended to double rows via a JOIN, but now contains one row with a DUMMY value of 'X'.

To see the log with changes inline, use the -p or --patch options. git log --patch Example (from Trello Scientist repository) ommit 8ea1452aca481a837d9504f1b2c77ad013367d25 Author: Raymond Chou <[email protected]> Date: Wed Mar 2 10:35:25 2016 -0800 fix readme error link diff ...

For JavaScript, here is the code we recommend for generating, persisting and retrieving a UUID. This could be wrapped in a function can called directly from the PUBNUB.init function rather than the two step inline solution below. // get/create/store UUID var UUID = PUBNUB.db.get('session') || (fun...

Overloading the bitwise NOT (~) is fairly simple. Scroll down for explanation Overloading outside of class/struct: T operator~(T lhs) { //Do operation return lhs; } Overloading inside of class/struct: T operator~() { T t(*this); //Do operation return t; } Note...

#include <stdio.h> #define is_const_int(x) _Generic((&x), \ const int *: "a const int", \ int *: "a non-const int", \ default: "of other type") int main(void) { const int i = 1; int j = 1; double...

A lambda expression provides a concise way to create simple function objects. A lambda expression is a prvalue whose result object is called closure object, which behaves like a function object. The name 'lambda expression' originates from lambda calculus, which is a mathematical formalism invented...

Tuples group multiple values into a single compound value. The values within a tuple can be of any type and do not have to be of the same type as each other. Tuples are created by grouping any amount of values: let tuple = ("one", 2, "three") // Values are read using index n...

If you want a function to be able to throw errors, you need to add the throws keyword after the parentheses that hold the arguments: func errorThrower()throws -> String {} When you want to throw an error, use the throw keyword: func errorThrower()throws -> String { if true { retur...

In this example we're going to look at testing webhook notifications in sandbox, using ngrok to provide a tunnel for our Node HTTP listener, running on localhost, to the internet. For this example, we're going to be using Node to set up notification webhooks for payment events (such as a payment bei...

Writing bytes to an OutputStream one byte at a time OutputStream stream = object.getOutputStream(); byte b = 0x00; stream.write( b ); Writing a byte array byte[] bytes = new byte[] { 0x00, 0x00 }; stream.write( bytes ); Writing a section of a byte array int offset = 1; int length = ...

This sample will show you how to update an existing webhook forwarding URL (where the notifications should be POSTed to). To run this, you should have the ID provided back by PayPal when you first created your webhooks. First, add the PayPal SDK and configure the environment (sandbox below). var p...

Since the new line separator varies from platform to platform (e.g. \n on Unix-like systems or \r\n on Windows) it is often necessary to have a platform-independent way of accessing it. In Java it can be retrieved from a system property: System.getProperty("line.separator") Java SE 7 ...

Java SE 7 byte[] bytes = { 0x48, 0x65, 0x6c, 0x6c, 0x6f }; try(FileOutputStream stream = new FileOutputStream("Hello world.txt")) { stream.write(bytes); } catch (IOException ioe) { // Handle I/O Exception ioe.printStackTrace(); } Java SE 7 byte[] bytes = { 0x48, ...

Streams provide the most direct access to the binary content, so any InputStream / OutputStream implementations always operate on ints and bytes. // Read a single byte from the stream int b = inputStream.read(); if (b >= 0) { // A negative value represents the end of the stream, normal values ...

With Stream Controller add-on enabled, you can use Channel Groups to subscribe to a 1000's of channels from a single client. You do this by creating a channel group and adding channels to the channel group. We'll assume pubnub variable has been initialized properly with your keys. Create a generic ...

Note that all bitwise operations operate on 32-bit integers by passing any operands to the internal function ToInt32. Bitwise or var a; a = 0b0011 | 0b1010; // a === 0b1011 // truth table // 1010 | (or) // 0011 // 1011 (result) Bitwise and a = 0b0011 & 0b1010; // a === 0b0010 // t...