Tutorial by Examples: st

This example is a quick setup of Angular 2 and how to generate a quick example project. Prerequisites: Node.js v4 or greater. npm v3 or greater or yarn. Open a terminal and run the commands one by one: npm install -g @angular/cli or yarn global add @angular/cli depending on your choi...

The main difference is that double-quoted String literals support string interpolations and the full set of escape sequences. For instance, they can include arbitrary Ruby expressions via interpolation: # Single-quoted strings don't support interpolation puts 'Now is #{Time.now}' # Now is #{Time...

Ruby provides several ways to create a String object. The most common way is using single or double quotes to create a "string literal": s1 = 'Hello' s2 = "Hello" The main difference is that double-quoted string literals are a little bit more flexible as they support interpo...

Concatenate strings with the + operator: s1 = "Hello" s2 = " " s3 = "World" puts s1 + s2 + s3 # => Hello World s = s1 + s2 + s3 puts s # => Hello World Or with the << operator: s = 'Hello' s << ' ' s << 'World' puts s # => ...

The double-quoted delimiter " and %Q sequence supports string interpolation using #{ruby_expression}: puts "Now is #{Time.now}" # Now is Now is 2016-07-21 12:47:45 +0200 puts %Q(Now is #{Time.now}) # Now is Now is 2016-07-21 12:47:45 +0200

By default, all the required libraries for build ASP.NET applications are included during the installation of Visual Studio. If a newer version of ASP.NET is released that was not included with Visual Studio, you can download the appropriate SDK library from Microsoft, which will include all the nec...

With any variadic function, the function must know how to interpret the variable arguments list. With the printf() or scanf() functions, the format string tells the function what to expect. The simplest technique is to pass an explicit count of the other arguments (which are normally all the same ...

The Dart SDK includes everything you need to write and run Dart code: VM, libraries, analyzer, package manager, doc generator, formatter, debugger, and more. If you are doing web development, you will also need Dartium. Automated installation and updates Installing Dart on Windows Installing Da...

Overview Unity runs on Windows and Mac. There is also a Linux alpha version available. There are 4 different payment plans for Unity: Personal - Free (see below) Plus - $35 USD per month per seat (see below) Pro - $125 USD per month per seat - After subscribing to the Pro plan for 24 consecut...

In your Visual Studio open the Solution Explorer window then right click on your project then choose Manage NuGet Packages from the menu: In the window that opens type EntityFramework in the search box in the top right. Or if you are using Visual Studio 2015 you'll see something like this: ...

The static (compile-time) type is used rather than the dynamic (run-time type) to match parameters. public class Base { public virtual string GetName() { return "Base"; } } public class Derived : Base { public override string GetName() { ...

It is possible to treat a GoogleMap as an Android view if we make use of the provided MapView class. Its usage is very similar to MapFragment. In your layout use MapView as follows: <com.google.android.gms.maps.MapView xmlns:android="http://schemas.android.com/apk/res/android" ...

What is Ubuntu Ubuntu is an open source software platform, but colloquially, when Ubuntu is referred to it's mainly toward the Ubuntu operating system. Ubuntu is based on Debian and uses the same package management system (deb and apt). Installation So you want to give Ubuntu a try! That's gr...

You may need to convert a Stream emitting Optional to a Stream of values, emitting only values from existing Optional. (ie: without null value and not dealing with Optional.empty()). Optional<String> op1 = Optional.empty(); Optional<String> op2 = Optional.of("Hello World");...

The function php_sapi_name() and the constant PHP_SAPI both return the type of interface (Server API) that is being used by PHP. They can be used to restrict the execution of a script to the command line, by checking whether the output of the function is equal to cli. if (php_sapi_name() === 'cli')...

A class marked with the keyword abstract cannot be instantiated. A class must be marked as abstract if it contains abstract members or if it inherits abstract members that it doesn't implement. A class may be marked as abstract even if no abstract members are involved. Abstract classes are usually...

preg_match checks whether a string matches the regular expression. $string = 'This is a string which contains numbers: 12345'; $isMatched = preg_match('%^[a-zA-Z]+: [0-9]+$%', $string); var_dump($isMatched); // bool(true) If you pass in a third parameter, it will be populated with the matchi...

NSString has a length property to get the number of characters. NSString *string = @"example"; NSUInteger length = string.length; // length equals 7 As in the Splitting Example, keep in mind that NSString uses UTF-16 to represent characters. The length is actually just the numbe...

Rails uses sqlite3 as the default database, but you can generate a new rails application with a database of your choice. Just add the -d option followed by the name of the database. $ rails new MyApp -T -d postgresql This is a (non-exhaustive) list of available database options: mysql oracle...

interface IFoo { } class Foo : IFoo { } class Bar : IFoo { } var item0 = new Foo(); var item1 = new Foo(); var item2 = new Bar(); var item3 = new Bar(); var collection = new IFoo[] { item0, item1, item2, item3 }; Using OfType var foos = collection.OfType<Foo>(); // result: IEnum...