Tutorial by Examples: nd

Bear in mind that declaring a destructor inhibits the compiler from generating implicit move constructors and move assignment operators. If you declare a destructor, remember to also add appropriate definitions for the move operations. Furthermore, declaring move operations will suppress the genera...

Define your class that will represent your custom error. public class ErrorDto { public int Code { get; set; } public string Message { get; set; } // other fields public override string ToString() { return JsonConvert.SerializeObject(this); } } Then put nex...

With the rgdal package it is possible to import and export shapfiles with R. The function readOGR can be used to imports shapfiles. If you want to import a file from e.g. ArcGIS the first argument dsn is the path to the folder which contains the shapefile. layer is the name of the shapefile without...

The packages foreign and haven can be used to import and export files from a variety of other statistical packages like Stata, SPSS and SAS and related software. There is a read function for each of the supported data types to import the files. # loading the packages library(foreign) library(have...

In C#, there are two different kinds of equality: reference equality and value equality. Value equality is the commonly understood meaning of equality: it means that two objects contain the same values. For example, two integers with the value of 2 have value equality. Reference equality means that ...

There are few approaches available there: You can subscribe for keyboard appearance events notifications and change offset manually: //Swift 2.0+ override func viewDidLoad() { super.viewDidLoad() NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(YourVCClas...

To show some content in a new window, a Stage needs to be created. After creation and initialisation show or showAndWait needs to be called on the Stage object: // create sample content Rectangle rect = new Rectangle(100, 100, 200, 300); Pane root = new Pane(rect); root.setPrefSize(500, 500); ...

An alternative to extending Enumeration is using sealed case objects: sealed trait WeekDay object WeekDay { case object Mon extends WeekDay case object Tue extends WeekDay case object Wed extends WeekDay case object Thu extends WeekDay case object Fri extends WeekDay case objec...

To avoid verbose null checking, the ?. operator has been introduced in the language. The old verbose syntax: If myObject IsNot Nothing AndAlso myObject.Value >= 10 Then Can be now replaced by the concise: If myObject?.Value >= 10 Then The ? operator is particularly powerful when you...

The number of seconds from the current date and time for the new date. Use a negative value to specify a date before the current date. For doing this we have a method named dateWithTimerIntervalSinceNow(seconds: NSTimeInterval) -> NSDate (Swift) or + (NSDate*)dateWithTimeIntervalSinceNow:(NSTime...

To get the timestamp in seconds Math.floor((new Date().getTime()) / 1000)

To spawn a new process in which you need unbuffered output (e.g. long-running processes which might print output over a period of time rather than printing and exiting immediately), use child_process.spawn(). This method spawns a new process using a given command and an array of arguments. The retu...

"dependencies": { "module-name": "0.1.0" } exact: 0.1.0 will install that specific version of the module. newest minor version: ^0.1.0 will install the newest minor version, for example 0.2.0, but won't install a module with a higher major version e.g. 1.0.0 newe...

This command will drop index in the table. It works on SAP ASE server. Syntax: DROP INDEX [table name].[index name] Example: DROP INDEX Cars.index_1

Post::find()->all(); // SELECT * FROM post or the shorthand (Returns an active record model instance by a primary key or an array of column values.) Post::findAll(condition); returns an array of ActiveRecord instances. Find All with where Condition $model = User::find() ->w...

You have to keep the operator precedence in mind when using await keyword. Imagine that we have an asynchronous function which calls another asynchronous function, getUnicorn() which returns a Promise that resolves to an instance of class Unicorn. Now we want to get the size of the unicorn using th...

The fetch function does not send cookies by default. There are two possible ways to send cookies: Only send cookies if the URL is on the same origin as the calling script. fetch('/login', { credentials: 'same-origin' }) Always send cookies, even for cross-origin calls. fetch('htt...

The Protractor API allows CSS element locators to use the jQuery-like shortcut notation $(). Normal CSS Element Locator: element(by.css('h1.documentation-text[ng-bind="title"]')); element(by.css('[ng-click="submit"])); Shortcut $() CSS Element Locator: $('h1.documentatio...

This example shows how to check permissions at runtime in Android 6 and later. public static final int MULTIPLE_PERMISSIONS = 10; // code you want. String[] permissions = new String[] { Manifest.permission.WRITE_EXTERNAL_STORAGE, Manifest.permission.CAMERA, Manifest.permission.ACC...

Examples below are given in Ruby, but same matchers should be available in any modern language. Let’s say we have the string "AℵNaïve", produced by Messy Artificial Intelligence. It consists of letters, but generic \w matcher won’t match much: ▶ "AℵNaïve"[/\w+/] #⇒ "A&q...