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// decode NSString *string = [[NSString alloc] initWithData:utf8Data encoding:NSUTF8StringEncoding]; // encode NSData *utf8Data = [string dataUsingEncoding:NSUTF8StringEncoding]; Some supported encodings are: NSASCIIStringEncoding NSUTF8StringEnc...

Download Qt for Linux Open Source Version Go to https://www.qt.io/download-open-source/ and click on Download Now, make sure that you are downloading the Qt installer for Linux. A file with the name qt-unified-linux-x-online.run will be downloaded, then add exec permission chmod +x qt-unified-...

There are 5 different types (MKMapType), MKMapView can display. iPhone OS 3 .standard Displays a street map that shows the position of all roads and some road names. Swift 2 mapView.mapType = .Standard Swift 3 mapView.mapType = .standard Objective-C _mapView.mapType = MKMapTypeStandard;...

The for and while compound statements (loops) can optionally have an else clause (in practice, this usage is fairly rare). The else clause only executes after a for loop terminates by iterating to completion, or after a while loop terminates by its conditional expression becoming false. for i in r...

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 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 = ...

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...

enum MyEnum { One, Two, Three } foreach(MyEnum e in Enum.GetValues(typeof(MyEnum))) Console.WriteLine(e); This will print: One Two Three

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...

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...

HTML <div class="translate"></div> CSS .translate { width: 100px; height: 100px; background: teal; transform: translate(200px, 50%); } This example will move the div by 200px on the X axis and by 100px * 50% = 50px on the Y axis. You can also spe...

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...

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 ...

manifest.json gives information about the extension, such as the most important files and the capabilities that the extension might use. Among the supported manifest fields for extensions, the following three are required. { "manifest_version": 2, "name": "My Exte...

CSS div{ width: 150px; height:150px; background-color: red; transition: background-color 1s; } div:hover{ background-color: green; } HTML <div></div> This example will change the background color when the div is hovered the background-color change will...

Directives are one of the most powerful features of angularjs. Custom angularjs directives are used to extend functionality of html by creating new html elements or custom attributes to provide certain behavior to an html tag. directive.js // Create the App module if you haven't created it yet va...

There is already a function sum(). As a result, if we name a variable with the same name sum = 1+3; and if we try to use the function while the variable still exists in the workspace A = rand(2); sum(A,1) we will get the cryptic error: Subscript indices must either be real positive integer...