Tutorial by Examples: u

Requirements: Docker can be installed on any Linux with a kernel of at least version 3.10. Docker is supported on the following 64-bit versions of Ubuntu Linux: Ubuntu Xenial 16.04 (LTS) Ubuntu Wily 15.10 Ubuntu Trusty 14.04 (LTS) Ubuntu Precise 12.04 (LTS) Easy Installation Note: Installi...

Custom sigils can be made by creating a method sigil_X where X is the letter you want to use (this can only be a single letter). defmodule Sigils do def sigil_j(string, options) do # Split on the letter p, or do something more useful String.split string, "p" end # Use t...

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...

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...

Guard clauses enables us to check the arguments before executing the function. Guard clauses are usually preferred to if and cond due to their readability, and to make a certain optimization technique easier for the compiler. The first function definition where all guards match is executed. Here is...

You can pass default parameters to any named function using the syntax: param \\ value: defmodule Example do def func(p1, p2 \\ 2) do IO.inspect [p1, p2] end end Example.func("a") # => ["a", 2] Example.func("b", 4) # => ["b", ...

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...

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 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 { @...

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;...

If you have both Python 3 and Python 2 installed, you can specify which version of Python you would like pip to use. This is useful when packages only support Python 2 or 3 or when you wish to test with both. If you want to install packages for Python 2, run either: pip install [package] or: p...

Linux has a command for almost any tasks and most of them are intuitive and easily interpreted. Getting Help in Linux CommandUsabilityman <name>Read the manual page of <name>.man <section> <name>Read the manual page of <name>, related to the given section.man -k <e...

Corner radius for all 4 edges: UIBezierPath* rectanglePath = [UIBezierPath bezierPathWithRoundedRect: CGRectMake(x,y,width,height) cornerRadius: 11]; [UIColor.grayColor setFill]; [rectanglePath fill]; Corner radius for top-left edge: UIBezierPath* rectanglePath = [UIBezierPath bezierPat...

For a simple circle: UIBezierPath* ovalPath = [UIBezierPath bezierPathWithOvalInRect: CGRectMake(0,0,50,50)]; [UIColor.grayColor setFill]; [ovalPath fill]; Swift: let ovalPath = UIBezierPath(ovalInRect: CGRect(x: 0, y: 0, width: 50, height: 50)) UIColor.grayColor().setFill() ovalPath.fill...

For bezier path to get resized based on the view frame, override the drawRect of view that you are drawing the bezier path : - (void)drawRect:(CGRect)frame { UIBezierPath* rectanglePath = [UIBezierPath bezierPathWithRect: CGRectMake(CGRectGetMinX(frame), CGRectGetMinY(frame), CGRectGetWidth(f...

Consider a simple rectangle that is drawn by the bezier path. UIBezierPath* rectanglePath = [UIBezierPath bezierPathWithRect: CGRectMake(x,y,width,height)]; [UIColor.grayColor setFill]; [rectanglePath fill]; Basic Outer-fill shadow: CGContextRef context = UIGraphicsGetCurrentContext();...