Tutorial by Examples: io

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...

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 = ...

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...

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(...

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; } ...

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...

You can handle multiple errors in the same rescue declaration: begin # an execution that may fail rescue FirstError, SecondError => e # do something if a FirstError or SecondError occurs end You can also add multiple rescue declarations: begin # an execution that may fail rescue ...

with other sets # Intersection {1, 2, 3, 4, 5}.intersection({3, 4, 5, 6}) # {3, 4, 5} {1, 2, 3, 4, 5} & {3, 4, 5, 6} # {3, 4, 5} # Union {1, 2, 3, 4, 5}.union({3, 4, 5, 6}) # {1, 2, 3, 4, 5, 6} {1, 2, 3, 4, 5} | {3, 4, 5, 6} # {1, 2, 3, 4, 5, 6} # Difference ...

Substitutability is a principle in object-oriented programming introduced by Barbara Liskov in a 1987 conference keynote stating that, if class B is a subclass of class A, then wherever A is expected, B can be used instead: class A {...} class B extends A {...} public void method(A obj) {...} ...

Go to Install Neo4j which should detect the OS platform via your web browser, download and follow the usual installation instructions for your OS. Neo4j was created with Java, therefore will run on any platform with Java installed, however the Neo4j team has simplified installation by providing eas...

Today Fortran is mainly used for numerical computation. This very simple example illustrates the basic program structure to solve quadratic equations: program quadratic !a comment !should be present in every separate program unit implicit none real :: a, b, c real :: discriminant...

Introduction SharePoint 2016 is the version 16 release of the SharePoint product family. It was released on May 4, 2016. This example covers the installation of SharePoint 2016 using the Single Server Farm configuration. This configuration covers the basics of setting up a SharePoint farm without t...

Detailed instructions on getting ironpython set up or installed. Install IronPython Just download the newest version from http://ironpython.net and follow the instructions from the msi package. This package will setup everything you need to start working with ironpython.