Tutorial by Examples: nd

Basic Random Number Generation

The function rand() can be used to generate a pseudo-random integer value between 0 and RAND_MAX (0 and RAND_MAX included). srand(int) is used to seed the pseudo-random number generator. Each time rand() is seeded wih the same seed, it must produce the same sequence of values. It should only be see...

Redirecting standard output

> redirect the standard output (aka STDOUT) of the current command into a file or another descriptor. These examples write the output of the ls command into the file file.txt ls >file.txt > file.txt ls The target file is created if it doesn't exists, otherwise this file is truncated. ...

Redirecting both STDOUT and STDERR

File descriptors like 0 and 1 are pointers. We change what file descriptors point to with redirection. >/dev/null means 1 points to /dev/null. First we point 1 (STDOUT) to /dev/null then point 2 (STDERR) to whatever 1 points to. # STDERR is redirect to STDOUT: redirected to /dev/null, # effect...

Append vs Truncate

Truncate > Create specified file if it does not exist. Truncate (remove file's content) Write to file $ echo "first line" > /tmp/lines $ echo "second line" > /tmp/lines $ cat /tmp/lines second line Append >> Create specified file if it does not e...

Extending Native Elements

It's possible to extent native elements, but their descendants don't get to have their own tag names. Instead, the is attribute is used to specify which subclass an element is supposed to use. For example, here's an extension of the <img> element which logs a message to the console when it's l...

Event Bubbling and Capturing

Events fired on DOM elements don't just affect the element they're targeting. Any of the target's ancestors in the DOM may also have a chance to react to the event. Consider the following document: <!DOCTYPE html> <html> <head> <meta charset="utf-8" /> </hea...
DOM • Events

Downloading a file with every error case handled using the SwiftyDropbox library

Dropbox.authorizedClient!.files.download(path: path, destination: destination).response { response, error in if let (metadata, url) = response { print("*** Download file ***") print("Downloaded file name: \(metadata.name)") print("Downloaded f...

Uploading a file from NSData with every error case handled using the SwiftyDropbox library

This uses the SwiftyDropbox library to upload a file from a NSData to the Dropbox account, using upload sessions for larger files, handling every error case: import UIKit import SwiftyDropbox class ViewController: UIViewController { // replace this made up data with the real data le...

Sharing a folder with every error case handled using the SwiftyDropbox library

This uses the SwiftyDropbox library to share a folder, handling every error case: Dropbox.authorizedClient!.sharing.shareFolder(path: "/folder_path").response { response, error in if let result = response { print("response: \(result)") } else if let callError ...

Inviting a member to a shared folder with every error case handled using the SwiftyDropbox library

let toInvite = [Sharing.AddMember(member: Sharing.MemberSelector.Email("<EMAIL_ADDRESS_TO_INVITE>"))] Dropbox.authorizedClient!.sharing.addFolderMember(sharedFolderId: "<SHARED_FOLDER_ID>", members: toInvite).response { response, error in if (response != nil...

Listing the root folder via curl in PHP and the cURL extension

<?php $parameters = array('path' => '','include_deleted' => true,'recursive' => true); $headers = array('Authorization: Bearer <ACCESS_TOKEN>', 'Content-Type: application/json'); $curlOptions = array( CURLOPT_HTTPHEADER => $headers, C...

Listing the root folder using the SwiftyDropbox library, distinguishing files and folders in the response

Dropbox.authorizedClient!.files.listFolder(path: "").response { response, error in print("*** List folder ***") if let result = response { print("Folder contents:") for entry in result.entries { print(entry.name) if ...

Attempting to list a non-existant folder using the SwiftyDropbox library, as an example of error handling

// List folder Dropbox.authorizedClient!.files.listFolder(path: "/nonexistantpath").response { response, error in print("*** List folder ***") if let result = response { print("Folder contents:") for entry in result.entries { pr...

Serializing and restoring class instances

You can use a custom toJSON method and reviver function to transmit instances of your own class in JSON. If an object has a toJSON method, its result will be serialized instead of the object itself. 6 function Car(color, speed) { this.color = color; this.speed = speed; } Car.prototype.to...

Converting between Blobs and ArrayBuffers

JavaScript has two primary ways to represent binary data in the browser. ArrayBuffers/TypedArrays contain mutable (though still fixed-length) binary data which you can directly manipulate. Blobs contain immutable binary data which can only be accessed through the asynchronous File interface. Conver...

Binding `this` and arguments

5.1 When you take a reference to a method (a property which is a function) in JavaScript, it usually doesn't remember the object it was originally attached to. If the method needs to refer to that object as this it won't be able to, and calling it will probably cause a crash. You can use the .bind...

Basic interpolation and multiline strings

Template literals are a special type of string literal that can be used instead of the standard '...' or "...". They are declared by quoting the string with backticks instead of the standard single or double quotes: `...`. Template literals can contain line breaks and arbitrary expression...

Class and instance variables

Instance variables are unique for each instance, while class variables are shared by all instances. class C: x = 2 # class variable def __init__(self, y): self.y = y # instance variable C.x # 2 C.y # AttributeError: type object 'C' has no attribute 'y' c1 = C(3) c1....

Bound, unbound, and static methods

The idea of bound and unbound methods was removed in Python 3. In Python 3 when you declare a method within a class, you are using a def keyword, thus creating a function object. This is a regular function, and the surrounding class works as its namespace. In the following example we declare method ...

Loading TrustStore and KeyStore from InputStream

public class TrustLoader { public static void main(String args[]) { try { //Gets the inputstream of a a trust store file under ssl/rpgrenadesClient.jks //This path refers to the ssl folder in the jar file, in a jar file in the same directory ...

Page 9 of 236

logo rip
SUPPORT & PARTNERS
STAY CONNECTED

Get monthly updates about new articles, cheatsheets, and tricks.