There is currently a proposal (not yet part of the ECMAScript standard) to add a finally callback to promises that will be executed regardless of whether the promise is fulfilled or rejected. Semantically, this is similar to the finally clause of the try block.
You would usually use this functional...
Protocols enable polymorphism in Elixir. Define protocols with defprotocol:
defprotocol Log do
def log(value, opts)
end
Implement a protocol with defimpl:
require Logger
# User and Post are custom structs
defimpl Log, for: User do
def log(user, _opts) do
Logger.info "User: ...
Use & to capture functions from other modules. You can use the captured functions directly as function parameters or within anonymous functions.
Enum.map(list, fn(x) -> String.capitalize(x) end)
Can be made more concise using &:
Enum.map(list, &String.capitalize(&1))
Captu...
We often encounter a situation where a property we're trying to extract doesn't exist in the object/array, resulting in a TypeError (while destructuring nested objects) or being set to undefined. While destructuring we can set a default value, which it will fallback to, in case of it not being found...
We are not limited to destructuring an object/array, we can destructure a nested object/array.
Nested Object Destructuring
var obj = {
a: {
c: 1,
d: 3
},
b: 2
};
var {
a: {
c: x,
d: y
},
b: z
} = obj;
console.log(x, y, z); // 1,3,2
Nested Array ...
\documentclass{article}% or book, report, ...
\begin{document}
See \cite{citeA} or \cite{citeB} or \cite{citeA, citeB}.
\begin{thebibliography}{x}
% \bibitem{<biblabel>} <citation>
\bibitem{citeA}
{\scshape Author, A}, {\itshape A title}, Journal of So-and-So, 2000....
round() tie breaking
In Python 2, using round() on a number equally close to two integers will return the one furthest from 0. For example:
Python 2.x2.7
round(1.5) # Out: 2.0
round(0.5) # Out: 1.0
round(-0.5) # Out: -1.0
round(-1.5) # Out: -2.0
In Python 3 however, round() will retur...
using System;
namespace TypeConversionApplication
{
class ExplicitConversion
{
static void Main(string[] args)
{
double d = 5673.74;
int i;
// cast double to int.
i = (int)d;
Console.WriteLine(i);
Cons...
An Interface's function known as a "contract" of functionality. It means that it declares properties and methods but it doesn't implement them.
So unlike classes Interfaces:
Can't be instantiated
Can't have any functionality
Can only contain methods * (Properties and Events are metho...
Don't you hate it when interfaces pollute you class with too many members you don't even care about? Well I got a solution! Explicit Implementations
public interface IMessageService {
void OnMessageRecieve();
void SendMessage();
string Result { get; set; }
int Encoding { get; se...
Dictionary<TKey, TValue> is a map. For a given key there can be one value in the dictionary.
using System.Collections.Generic;
var people = new Dictionary<string, int>
{
{ "John", 30 }, {"Mary", 35}, {"Jack", 40}
};
// Reading data
Console.Wri...
To register your device for push notifications, add the following code to your AppDelegate file in didFinishLaunchingWithOptions method:
Swift
func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
// Override point for c...
Strict-Transport-Security: max-age=31536000; includeSubDomains
Strict-Transport-Security is a promise to the browser that all future requests to this domain will be secure.
For the future time period max-age:
All outgoing HTTP requests from the browser will be converted to HTTPS on the client...
Strict-Transport-Security: max-age=31536000; includeSubDomains; preload
HSTS is activated only after a successful HTTPS request to the server with a valid certificate. There is still a risk of a first-time user accessing the site, at which point a Man-in-the-Middle attack is possible.
To make th...
Note: Before upgrading your Rails app, always make sure to save your code on a version control system, such as Git.
To upgrade from Rails 4.2 to Rails 5.0, you must be using Ruby 2.2.2 or newer. After upgrading your Ruby version if required, go to your Gemfile and change the line:
gem 'rails', '...
Strings Array
When selecting a value in the select dropdown and providing an array of strings, the selected value will be bound to the select element's value property as a string that we can display using string interpolation.
export class MyViewModel {
animals = [];
favouriteAnimal = nu...
