Tutorial by Examples: basics

using is syntactic sugar that allows you to guarantee that a resource is cleaned up without needing an explicit try-finally block. This means your code will be much cleaner, and you won't leak non-managed resources. Standard Dispose cleanup pattern, for objects that implement the IDisposable interf...

See RFC 2030 for details on the SNTP protocol. using System; using System.Globalization; using System.Linq; using System.Net; using System.Net.Sockets; class SntpClient { const int SntpPort = 123; static DateTime BaseDate = new DateTime(1900, 1, 1); static void Main(string[...

// Connect to a target server using your ConnectionMultiplexer instance IServer server = conn.GetServer("localhost", 6379); // Write out each key in the server foreach(var key in server.Keys()) { Console.WriteLine(key); }

About Protocols A Protocol specifies initialisers, properties, functions, subscripts and associated types required of a Swift object type (class, struct or enum) conforming to the protocol. In some languages similar ideas for requirement specifications of subsequent objects are known as ‘interfaces...

struct Repository { let identifier: Int let name: String var description: String? } This defines a Repository struct with three stored properties, an integer identifier, a string name, and an optional string description. The identifier and name are constants, as they've been decla...

Closures (also known as blocks or lambdas) are pieces of code which can be stored and passed around within your program. let sayHi = { print("Hello") } // The type of sayHi is "() -> ()", aka "() -> Void" sayHi() // prints "Hello" Like other fun...

Functions in Swift may return values, throw errors, or both: func reticulateSplines() // no return value and no error func reticulateSplines() -> Int // always returns a value func reticulateSplines() throws // no return value, but may throw an error func reticulat...

Array is an ordered collection type in the Swift standard library. It provides O(1) random access and dynamic reallocation. Array is a generic type, so the type of values it contains are known at compile time. As Array is a value type, its mutability is defined by whether it is annotated as a var (...

For any iterable (for eg. a string, list, etc), Python allows you to slice and return a substring or sublist of its data. Format for slicing: iterable_name[start:stop:step] where, start is the first index of the slice. Defaults to 0 (the index of the first element) stop one past the last in...

Data Manipulation Language (DML for short) includes operations such as INSERT, UPDATE and DELETE: -- Create a table HelloWorld CREATE TABLE HelloWorld ( Id INT IDENTITY, Description VARCHAR(1000) ) -- DML Operation INSERT, inserting a row into the table INSERT INTO HelloWorld (D...

The Spinner can be reskinned according to your own style requirements using a Nine Patch. As an example, see this Nine Patch: As you can see, it has 3 extremely small areas of stretching marked. The top border has only left of the icon marked. That indicates that I want the left side (complete ...

The term "IFrame" means Inline Frame. It can be used to include another page in your page. This will yield a small frame which shows the exact contents of the base.html. <iframe src="base.html"></iframe>

A class is a user-defined type. A class is introduced with the class, struct or union keyword. In colloquial usage, the term "class" usually refers only to non-union classes. A class is a collection of class members, which can be: member variables (also called "fields"), mem...

Properties can be added to a class or struct (technically enums too, see "Computed Properties" example). These add values that associate with instances of classes/structs: class Dog { var name = "" } In the above case, instances of Dog have a property named name of type...

Using the threading module, a new thread of execution may be started by creating a new threading.Thread and assigning it a function to execute: import threading def foo(): print "Hello threading!" my_thread = threading.Thread(target=foo) The target parameter references the fun...

A typical email has three main components: A recipient (represented as an email address) A subject A message body Sending mail in PHP can be as simple as calling the built-in function mail(). mail() takes up to five parameters but the first three are all that is required to send an email (al...

A positive lookahead (?=123) asserts the text is followed by the given pattern, without including the pattern in the match. Similarly, a positive lookbehind (?<=123) asserts the text is preceded by the given pattern. Replacing the = with ! negates the assertion. Input: 123456 123(?=456) mat...

Before publishing a package you have to version it. npm supports semantic versioning, this means there are patch, minor and major releases. For example, if your package is at version 1.2.3 to change version you have to: patch release: npm version patch => 1.2.4 minor release: npm version min...

Razor code can be inserted anywhere within HTML code. Razor code blocks are enclosed in @{ ... }. Inline variable and functions start with @. Code inside the Razor brackets follow the normal C# or VB rules. Single line statement: @{ var firstNumber = 1; } Multi-line code block: @{ var sec...

What is Serialization Serialization is the process of converting an object's state (including its references) to a sequence of bytes, as well as the process of rebuilding those bytes into a live object at some future time. Serialization is used when you want to persist the object. It is also used b...