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Detailed instructions on getting Nativescript set up or installed. The following examples show the required steps to set up a Windows or OSX system and then sign post to troubleshooting guides in case you have any trouble. In addition, there are examples of how to set up recommended workflows, IDE...

To check for a precise number of elements in the collection def f(ints: Seq[Int]): String = ints match { case Seq() => "The Seq is empty !" case Seq(first) => s"The seq has exactly one element : $first" case Seq(first, second) => s"The...

Prerequisites: NodeJS and npm There are two ways of installing Webpack: globally or per-project. It is best to have the dependency installed per-project, as this will allow you to use different versions of webpack for each project and don't require user to have installed webpack globally. Install...

All Java exceptions are instances of classes in the Exception class hierarchy. This can be represented as follows: java.lang.Throwable - This is the base class for all exception classes. Its methods and constructors implement a range of functionality common to all exceptions. java.lang.Excep...

$fruit1 = ['apples', 'pears']; $fruit2 = ['bananas', 'oranges']; $all_of_fruits = array_merge($fruit1, $fruit2); // now value of $all_of_fruits is [0 => 'apples', 1 => 'pears', 2 => 'bananas', 3 => 'oranges'] Note that array_merge will change numeric indexes, but overwrite string...

A function defined as async is a function that can perform asynchronous actions but still look synchronous. The way it's done is using the await keyword to defer the function while it waits for a Promise to resolve or reject. Note: Async functions are a Stage 4 ("Finished") proposal on tr...

A Pseudo Distributed Cluster Setup Procedure Prerequisites Install JDK1.7 and set JAVA_HOME environment variable. Create a new user as "hadoop". useradd hadoop Setup password-less SSH login to its own account su - hadoop ssh-keygen << Press ENTER for all prompt...

A context manager is an object that is notified when a context (a block of code) starts and ends. You commonly use one with the with statement. It takes care of the notifying. For example, file objects are context managers. When a context ends, the file object is closed automatically: open_file = ...

In Python 2, an iterator can be traversed by using a method called next on the iterator itself: Python 2.x2.3 g = (i for i in range(0, 3)) g.next() # Yields 0 g.next() # Yields 1 g.next() # Yields 2 In Python 3 the .next method has been renamed to .__next__, acknowledging its “magic” ro...

SELECT * FROM Employees ORDER BY LName This statement will return all the columns from the table Employees. IdFNameLNamePhoneNumber2JohnJohnson24681012141JamesSmith12345678903MichaelWilliams1357911131 SELECT * FROM Employees ORDER BY LName DESC Or SELECT * FROM Employees ORDER BY LName ASC...

math modules includes two commonly used mathematical constants. math.pi - The mathematical constant pi math.e - The mathematical constant e (base of natural logarithm) >>> from math import pi, e >>> pi 3.141592653589793 >>> e 2.718281828459045 >>> P...

Windows Environment Install XAMPP or WAMP Download and Unzip the package from Codeigniter.com Extract all the document in the server space (htdocs or www directory) Mac Environment Install MAMP Download and Unzip the package from Codeigniter.com Extract all the document in the server sp...

Running the latest Liferay CE is straightforward: Go to https://www.liferay.com/downloads. Choose a bundle among the ones listed. For beginners, the Tomcat bundle is a good choice. Click in "Download." Unzip the download package whenever you find fit. The unzipped directory will...

With promises: function doTheThing() { return doOneThing() .then(doAnother) .then(doSomeMore) .catch(handleErrors) } With async functions: async function doTheThing() { try { const one = await doOneThing(); const another = await doAnother(...

Requirements: Protractor requires the following dependencies to be installed prior to installation: Java JDK 1.7 or higher Node.js v4 or higher Installation: Download and install Node.js from this URL: https://nodejs.org/en/ To see if the Node.js installation is successfull, you can go an...

Defining position as fixed we can remove an element from the document flow and set its position relatively to the browser window. One obvious use is when we want something to be visible when we scroll to the bottom of a long page. #stickyDiv { position:fixed; top:10px; left:10px; } ...

A context manager is any object that implements two magic methods __enter__() and __exit__() (although it can implement other methods as well): class AContextManager(): def __enter__(self): print("Entered") # optionally return an object return "A-ins...

To raise an exception use Kernel#raise passing the exception class and/or message: raise StandardError # raises a StandardError.new raise StandardError, "An error" # raises a StandardError.new("An error") You can also simply pass an error message. In this case, the message i...

A custom exception is any class that extends Exception or a subclass of Exception. In general, you should always extend StandardError or a descendant. The Exception family are usually for virtual-machine or system errors, rescuing them can prevent a forced interruption from working as expected. # ...

Use the begin/rescue block to catch (rescue) an exception and handle it: begin # an execution that may fail rescue # something to execute in case of failure end A rescue clause is analogous to a catch block in a curly brace language like C# or Java. A bare rescue like this rescues Stand...