Tutorial by Examples: e

In JSX expressions that contain both an opening tag and a closing tag, the content between those tags is passed as a special prop: props.children. There are several different ways to pass children: String Literals You can put a string between the opening and closing tags and props.children will ju...

Description: mov copies values of bits from source argument to destination argument. Common source/destination are registers, usually the fastest way to manipulate values with[in] CPU. Another important group of source_of/destination_for values is computer memory. Finally some immediate values m...

This is usually used for renaming or shortening long namespace references such referring to components of a library. namespace boost { namespace multiprecision { class Number ... } } namespace Name1 = boost::multiprecision; // Both Type declarations are equivale...

Alias Declaration are affected by preceding using statements namespace boost { namespace multiprecision { class Number ... } } using namespace boost; // Both Namespace are equivalent namespace Name1 = boost::multiprecision; namespace Name2 = multiprecision; ...

PyMongo is a native Python driver for MongoDB. Install PyMongo pip install pymongo Create a connection Use MongoClient to create a connection. MongoClient defaults to MongoDB instance running on localhost:27017 if not specified. from pymongo import MongoClient client = MongoClient() Acce...

For a circular View (in this case TextView) create a drawble round_view.xml in drawble folder: <?xml version="1.0" encoding="utf-8"?> <shape xmlns:android="http://schemas.android.com/apk/res/android" android:shape="oval"> <solid...

Php arrayiterator allows you to modify and unset the values while iterating over arrays and objects. Example: $array = ['1' => 'apple', '2' => 'banana', '3' => 'cherry']; $arrayObject = new ArrayObject($array); $iterator = $arrayObject->getIterator(); for($iterator; $iterator-...

To declare a single namespace with hierarchy use following example: namespace MyProject\Sub\Level; const CONNECT_OK = 1; class Connection { /* ... */ } function connect() { /* ... */ } The above example creates: constant MyProject\Sub\Level\CONNECT_OK class MyProject\Sub\Level\Connection...

GridView definition on ASPX page As shown below, first column of grid is defined as a checkbox column, which is conditionally cleared as shown in further examples below (the header checkbox is only for selecting/un-selecting all rows on current page, but same can be extended for all on grid easily)...

MongoDB stores data records as BSON documents. BSON is the binary representation of JSON. $ python >>> from pymongo import MongoClient >>> client = MongoClient() >>> col = client.mydb.test Create Insert a single document insert_one(document) >>> result = ...

Although not necessary in PHP however it is a very good practice to initialize variables. Uninitialized variables have a default value of their type depending on the context in which they are used: Unset AND unreferenced var_dump($unset_var); // outputs NULL Boolean echo($unset_bool ? "tr...

Fluent wait is a superclass of explicit wait (WebDriverWait) that is more configurable since it can accept an argument to the wait function. I'll pass on implicit wait, since it's a best practice to avoid it. Usage (Java): Wait wait = new FluentWait<>(this.driver) .withTimeout(drive...

Go to File > Settings > Keymap and select the Keymaps option from: Mac OS X Emacs Visual Studio Eclise Netbeans Jbuilder and others, to map the shortcuts to the wanted tool ones.

class UserUnsubscribeJob < ApplicationJob queue_as :default def perform(user) # this will happen later user.unsubscribe end end

instanceof requires that the variable is of type any. This code (try it): class Pet { } class Dog extends Pet { bark() { console.log("woof"); } } class Cat extends Pet { purr() { console.log("meow"); } } function example(foo: any) { ...

typeof is used when you need to distinguish between types number, string, boolean, and symbol. Other string constants will not error, but won't be used to narrow types either. Unlike instanceof, typeof will work with a variable of any type. In the example below, foo could be typed as number | str...

You can declare functions that serve as type guards using any logic you'd like. They take the form: function functionName(variableName: any): variableName is DesiredType { // body that returns boolean } If the function returns true, TypeScript will narrow the type to DesiredType in any bl...

This error message may be produced by the OpenSSH ssh client. It means that the TCP connection between the client and the server was abnormally closed by the server immediately after being accepted. Common reasons for this message include: The SSH server process is malfunctioning--for example, it...

This error message may be produced by the OpenSSH ssh client. It means that the TCP connection between the client and the server was closed by the server immediately after being accepted. This message generally indicates the SSH server has been configured not to accept connections from the client fo...

$ rails g job user_unsubscribe