Tutorial by Examples: n

Visual Studio Code is an open-source and feature-rich code editor from Microsoft. To set it up it for NativeScript development, open the Command Palette (F1 or ⌘+Shift+P) and type ext install NativeScript. Once the NativeScript extension is installed, the debugger should allow you to set breakpoint...

In the following example, the greet function inside Greeter module is run in a separate process: defmodule Greeter do def greet do IO.puts "Hello programmer!" end end iex> spawn(Greeter, :greet, []) Hello #PID<0.122.0> Here #PID<0.122.0> is the ...

Named Functions defmodule Math do # one way def add(a, b) do a + b end # another way def subtract(a, b), do: a - b end iex> Math.add(2, 3) 5 :ok iex> Math.subtract(5, 2) 3 :ok Private Functions defmodule Math do def sum(a, b) do a...

Elixir matches a function call to its body based on the value of its arguments. defmodule Math do def factorial(0): do: 1 def factorial(n): do: n * factorial(n - 1) end Here, factorial of positive numbers matches the second clause, while factorial(0) matches the first. (ignoring negat...

Enable USB Debugging on your device and from command line type adb devices. If everything is OK, the response should be: List of devices attached 1234567890 device Where 1234567890 is the device's id. If multiple devices are connected, you should see all of them: List of devices at...

Named vector can be created in several ways. With c: xc <- c('a' = 5, 'b' = 6, 'c' = 7, 'd' = 8) which results in: > xc a b c d 5 6 7 8 with list: xl <- list('a' = 5, 'b' = 6, 'c' = 7, 'd' = 8) which results in: > xl $a [1] 5 $b [1] 6 $c [1] 7 $d [1] 8 Wi...

Binding is the process of assigning an object to an identifier or variable name. Early binding (also known as static binding) is when an object declared in Excel is of a specific object type, such as a Worksheet or Workbook. Late binding occurs when general object associations are made, such as the ...

To clone a specific branch of a repository, type --branch <branch name> before the repository url: git clone --branch <branch name> <url> [directory] To use the shorthand option for --branch, type -b. This command downloads entire repository and checks out <branch name>. ...

An Option is a discriminated union with two cases, None or Some. type Option<'T> = Some of 'T | None

A sequence is a series of elements that can be enumerated. It is an alias of System.Collections.Generic.IEnumerable and lazy. It stores a series of elements of the same type (can be any value or object, even another sequence). Functions from the Seq.module can be used to operate on it. Here is a s...

Autoboxing can come at a substantial memory overhead. For example: Map<Integer, Integer> square = new HashMap<Integer, Integer>(); for(int i = 256; i < 1024; i++) { square.put(i, i * i); // Autoboxing of large integers } will typically consume substantial amount of memory (...

To change password of current user just type: sudo passwd It will ask you to enter your current password: [sudo] password for <user>: And then you will be asked to enter new password: Enter new UNIX password: And finally you will be asked to re-enter your password: Retype new UNIX...

Swift //Swift let viewController = UIViewController() let navigationController = UINavigationController(rootViewController: viewController) //Objective-C UIViewController *viewController = [[UIViewController alloc] init]; UINavigationController *navigationController = [[UINavigationControlle...

//Swift let fooViewController = UIViewController() navigationController?.pushViewController(fooViewController, animated: true) //Objective-C UIViewController *fooViewController = [[UIViewController alloc] init]; [navigationController pushViewController:fooViewController animated:YES];

As we know that we should use synchronized keyword to make execution of a method or block exclusive. But few of us may not be aware of one more important aspect of using synchronized and volatile keyword: apart from making a unit of code atomic, it also provides read / write barrier. What is this re...

Typically, when using UIControl or UIButton, we add a selector as a callback action for when an event occurs on a button or control, such as the user pressing the button or touching the control. For example, we would do the following: import UIKit class ViewController: UIViewController { @...

Go to editor (from tool window) Esc Switching focus to corresponding tool window Windows: Alt + <tool window number> OS X / macOS: Cmd + <tool window number> For example switching focus to the project window Windows: Alt + 1 OS X / macOS: Cmd + 1 Recent files popup Windows: Ctrl...

It is common within applications to need to have code like this : a = a + 1 or a = a * 2 There is an effective shortcut for these in place operations : a += 1 # and a *= 2 Any mathematic operator can be used before the '=' character to make an inplace operation : -= decrement the va...

YAML is a text based format allowing to store structured data in a hierarchy. YAML is designed to be human and machine readable with a minimum of overhead. The YAML specification can be found at yaml.org. There is also a reference card Comments start with # and go till newline, comments must be sep...

If you've got multiple implementations of the same interface, Spring can autowire them all into a collection object. I'm going to use an example using a Validator pattern1 Foo Class: public class Foo { private String name; private String emailAddress; private String errorMessage;...