Tutorial by Examples: i

Global Factory Function to Emulate a Parameterized Constructor

' Making a factory with parameter to the class Public Function new_Car(wheels) Set new_Car = New Car new_Car.Wheels = wheels End Function ' Creating a car through a factory Dim semiTrailer Set semiTrailer = new_Car(18)

vbscript • Using Classes

Conversion Specifiers for printing

Conversion SpecifierType of ArgumentDescriptioni, dintprints decimaluunsigned intprints decimalounsigned intprints octalxunsigned intprints hexadecimal, lower-caseXunsigned intprints hexadecimal, upper-casefdoubleprints float with a default precision of 6, if no precision is given (lower-case used f...

C Language • Formatted Input/Output

Load HTML string

Web views are useful to load locally generated HTML strings. NSString *html = @"<!DOCTYPE html><html><body>Hello World</body></html>"; [webView loadHTMLString:html baseURL:nil]; Swift let htmlString = "<h1>My First Heading</h1><p&gt...

iOS • UIWebView

Standard form vs Elvis form

// long form String sayHello(String name){ "Hello, ${name ? name : 'stranger'}." } // elvis String sayHello(String name){ "Hello, ${name ?: 'stranger'}." } Notice that the "elvis" format omits the "true" term because the original comparison...

groovy • Ternary and Elvis Operators

Assignment with %<>%

The magrittr package contains a compound assignment infix-operator, %<>%, that updates a value by first piping it into one or more rhs expressions and then assigning the result. This eliminates the need to type an object name twice (once on each side of the assignment operator <-). %<&gt...

R Language • Pipe operators (%>% and others)

Installing R

You might wish to install RStudio after you have installed R. RStudio is a development environment for R that simplifies many programming tasks. Windows only: Visual Studio (starting from version 2015 Update 3) now features a development environment for R called R Tools, that includes a live inter...

R Language • Getting started with R Language

Designing and drawing a Bezier Path

This example shows the process from designing the shape you want to drawing it on a view. A specific shap is used but the concepts you learn can be applied to any shape. How to draw a Bézier path in a custom view These are the main steps: Design the outline of the shape you want. Divide the ou...

iOS • UIBezierPath

Getting and Setting the Cursor Postition

Useful information The very beginning of the text field text: let startPosition: UITextPosition = textView.beginningOfDocument The very end of the text field text: let endPosition: UITextPosition = textView.endOfDocument The currently selected range: let selectedRange: UITextRange? = textV...

iOS • UITextView

Creating a UIBarButtonItem in the Interface Builder

The example below shows how to add a navigation bar button (called a UIBarButtonItem) in the Interface Builder. Add a Navigation Controller to your Storyboard Select your View Controller and then in the Xcode menu choose Editor > Embed In > Navigation Controller. Alternatively, you could ...

iOS • UIBarButtonItem

PHPUnit Data Providers

Test methods often need data to be tested with. To test some methods completely you need to provide different data sets for every possible test condition. Of course, you can do it manually using loops, like this: ... public function testSomething() { $data = [...]; foreach($data as $dat...

PHP • Unit Testing

Create an Xamarin Forms custom input control (no native required)

Below is an example of a pure Xamarin Forms custom control. No custom rendering is being done for this but could easily be implemented, in fact, in my own code, I use this very same control along with a custom renderer for both the Label and Entry. The custom control is a ContentView with a Label, ...

Xamarin.Forms • Creating custom controls

Make an Image tappable by adding a TapGestureRecognizer

There are a couple of default recognizers available in Xamarin.Forms, one of them is the TapGestureRecognizer. You can add them to virtually any visual element. Have a look at a simple implementation which binds to an Image. Here is how to do it in code. var tappedCommand = new Command(() => {...

Xamarin.Forms • Gestures

Zoom an Image with the Pinch gesture

In order to make an Image (or any other visual element) zoomable we have to add a PinchGestureRecognizer to it. Here is how to do it in code: var pinchGesture = new PinchGestureRecognizer(); pinchGesture.PinchUpdated += (s, e) => { // Handle the pinch }; image.GestureRecognizers.Add(pi...

Xamarin.Forms • Gestures

Show all of the zoomed Image content with the PanGestureRecognizer

When you have a zoomed Image (or other content) you may want to drag around the Image to show all of its content in the zoomed in state. This can be achieved by implementing the PanGestureRecognizer. From code this looks like so: var panGesture = new PanGestureRecognizer(); panGesture.PanUpdated...

Xamarin.Forms • Gestures

Basic Binding to ViewModel

EntryPage.xaml: <?xml version="1.0" encoding="utf-8" ?> <ContentPage xmlns="http://xamarin.com/schemas/2014/forms" xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml" xmlns:vm="clr-namespace:MyAssembly.ViewModel;a...

Xamarin.Forms • Data Binding

Valid Keys

Redis keys are binary-safe, so literally anything can be used as a key. The only limitations are that they must be less than 512MB. Examples of valid keys: 7 ++++ `~!@#$%^&*()-_=+ user:10134 search/9947372/?query=this%20is%20a%28test%29%20query <div id="div64"> Any othe...

redis • Redis Keys

Key Naming Schemes

For clarity and maintainability, it is often recommended to develop a system or schema for naming your Redis keys. Here are some examples of common and maintainable systems for naming your keys: user:10134 user:10134:favorites user:10134:friends user:10134:friends-of-friends user:10134 user:...

redis • Redis Keys

Adding a map in Xamarin.Forms (Xamarin Studio)

You can simply use the native map APIs on each platform with Xamarin Forms. All you need is to download the Xamarin.Forms.Maps package from nuget and install it to each project (including the PCL project). Maps Initialization First of all you have to add this code to your platform-specific project...

Xamarin.Forms • Working with Maps

IPython vs Jupyter

IPython has two parts to it: A command line interface that replaces the default python REPL and a way to run Python through the web browser as a graphical user interface. With the latest developments the browser part has been split into the Jupyter project that enables multiple programming language...

ipython • Getting started with ipython

Finding a string within a string

Using the System.String.Contains you can find out if a particular string exists within a string. The method returns a boolean, true if the string exists else false. string s = "Hello World"; bool stringExists = s.Contains("ello"); //stringExists =true as the string contains t...

C# Language • String Manipulation