Tutorial by Examples: r

Elements and attributes behave differently with respect to default namespaces. This is often the source of confusion. An attribute whose name has no prefix lives in no namespace, also when a default namespace is in scope. <?xml version="1.0"?> <foo attr="value" xmlns=...

<?xml version="1.0"?> <?speech-generator voice="Siri"?> <root xmlns:vocabulary="http://www.example.com/vocabulary"> <!-- These are the standard greetings --> <vocabulary:greetings> <vocabulary:greeting xml:lang="en-US&q...

Dim inputCode As Integer = Console.Read() Console.Read() awaits input from the user and, upon receipt, returns an integer value corresponding with the character code of the entered character. If the input stream is ended in some way before input can be obtained, -1 is returned instead.

Dim inputChar As ConsoleKeyInfo = Console.ReadKey() Console.ReadKey() awaits input from the user and, upon receipt, returns an object of class ConsoleKeyInfo, which holds information relevant to the character which the user provided as input. For detail regarding the information provided, visit t...

itertools.takewhile enables you to take items from a sequence until a condition first becomes False. def is_even(x): return x % 2 == 0 lst = [0, 2, 4, 12, 18, 13, 14, 22, 23, 44] result = list(itertools.takewhile(is_even, lst)) print(result) This outputs [0, 2, 4, 12, 18]. Not...

itertools.dropwhile enables you to take items from a sequence after a condition first becomes False. def is_even(x): return x % 2 == 0 lst = [0, 2, 4, 12, 18, 13, 14, 22, 23, 44] result = list(itertools.dropwhile(is_even, lst)) print(result) This outputs [13, 14, 22, 23, 44]. ...

C++11 Deriving a class may be forbidden with final specifier. Let's declare a final class: class A final { }; Now any attempt to subclass it will cause a compilation error: // Compilation error: cannot derive from final class: class B : public A { }; Final class may appear anywhere in cl...

You can easily add a breakpoint to your code by clicking on the grey column to the left of the line of your VBA code where you want execution to stop. A red dot appears in the column and the breakpoint code is also highlighted in red. You can add multiple breakpoints throughout your code and resumi...

In contrast of a full template specialization partial template specialization allows to introduce template with some of the arguments of existing template fixed. Partial template specialization is only available for template class/structs: // Common case: template<typename T, typename U> st...

This example will show you how to quickly get a hello world Aurelia application up and running using the Aurelia CLI. Prerequisites The Aurelia CLI is a Node.js based application, so make sure you install it first before proceeding. You will need Node.js 4.4.7 or later. You will also need a Git c...

A commonly used CSS/Javascript library is Bootstrap. To install it into your Aurelia CLI driven application first you need to install it using Npm. npm install bootstrap --save Because Bootstrap has a hard dependency on jQuery, we need to make sure we also have jQuery installed: npm install jqu...

While Value Converters can be comprised of either a toView or fromView method, in the below example we will be creating a basic Value Converter which just uses the toView method which accepts the value being sent to the view as the first argument. to-uppercase.js export class ToUppercaseValueConve...

A bi-directional value converter utilizes two methods in your Value Converter class: toView and fromView these methods are aptly named to signify which direction the data is flowing. In our example we will be creating a prepend Value Converter which will make sure that an amount entered in our app ...

A Value Converter can be used alongside other value converters and you can infinitely chain them using the | pipe separator. ${myString | toUppercase | removeCharacters:'&,%,-,+' | limitTo:25} The above theoretical example firstly applies toUppercase which capitalizes our string. Then it app...

The Groovy version of Hello World. println 'Hello World!'

When you use or, it will either return the first value in the expression if it's true, else it will blindly return the second value. I.e. or is equivalent to: def or_(a, b): if a: return a else: return b For and, it will return its first value if it's false, else it r...

Props are a way to pass information into a React component, they can have any type including functions - sometimes referred to as callbacks. In JSX props are passed with the attribute syntax <MyComponent userID={123} /> Inside the definition for MyComponent userID will now be accessible f...

Stateless components are getting their philosophy from functional programming. Which implies that: A function returns all time the same thing exactly on what is given to it. For example: const statelessSum = (a, b) => a + b; let a = 0; const statefulSum = () => a++; As you can see fro...

Create project using STS (Spring Starter Project) or Spring Initializr (at https://start.spring.io ). Add a Web Dependency in your pom.xml: <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId&...

Recursion occurs when a function call causes that same function to be called again before the original function call terminates. For example, consider the well-known mathematical expression x! (i.e. the factorial operation). The factorial operation is defined for all nonnegative integers as follows:...