Tutorial by Examples: d

The extension method to be called is determined at compile-time based on the reference-type of the variable being accessed. It doesn't matter what the variable's type is at runtime, the same extension method will always be called. open class Super class Sub : Super() fun Super.myExtension()...

A stub is a light weight test double that provides canned responses when methods are called. Where a class under test relies on an interface or base class an alternative 'stub' class can be implemented for testing which conforms to the interface. So, assuming the following interface, public inter...

Mocks are used when it is necessary to verify the interactions between the system under test and test doubles. Care needs to be taken to avoid creating overly brittle tests, but mocking can be particularly useful when the method to test is simply orchestrating other calls. This test verifies that ...

CREATE TABLE MyTableName ( Id INT, MyColumnName NVARCHAR(1000) ) GO INSERT INTO MyTableName (Id, MyColumnName) VALUES (1, N'Hello World!') GO

import shutil source='//192.168.1.2/Daily Reports' destination='D:\\Reports\\Today' shutil.copytree(source, destination) The destination directory must not exist already.

When an API is marked with NS_REFINED_FOR_SWIFT, it will be prefixed with two underscores (__) when imported to Swift: @interface MyClass : NSObject - (NSInteger)indexOfObject:(id)obj NS_REFINED_FOR_SWIFT; @end The generated interface looks like this: public class MyClass : NSObject { publ...

All Kotlin programs start at the main function. Here is an example of a simple Kotlin "Hello World" program: package my.program fun main(args: Array<String>) { println("Hello, world!") } Place the above code into a file named Main.kt (this filename is entirel...

To update a package use the following command: PM> Update-Package EntityFramework where EntityFramework is the name of the package to be updated. Note that update will run for all projects, and so is different from Install-Package EntityFramework which would install to "Default project&q...

Pull properties from an object passed into a function. This pattern simulates named parameters instead of relying on argument position. let user = { name: 'Jill', age: 33, profession: 'Pilot' } function greeting ({name, profession}) { console.log(`Hello, ${name} the ${pr...

The json_decode() function takes a JSON-encoded string as its first parameter and parses it into a PHP variable. Normally, json_decode() will return an object of \stdClass if the top level item in the JSON object is a dictionary or an indexed array if the JSON object is an array. It will also retur...

The json_encode function will convert a PHP array (or, since PHP 5.4, an object which implements the JsonSerializable interface) to a JSON-encoded string. It returns a JSON-encoded string on success or FALSE on failure. $array = [ 'name' => 'Jeff', 'age' => 20, 'active' => ...

In this example, we can use GROUP BY not only determined the sort of the rows returned, but also what rows are returned, since we're using TOP to limit the result set. Let's say we want to return the top 5 highest reputation users from an unnamed popular Q&A site. Without ORDER BY This query ...

This uses the Dropbox .NET SDK to download a file from the Dropbox API at the remote path /Homework/math/Prime_Numbers.txt to the local file Prime_Numbers.txt: using (var response = await client.Files.DownloadAsync("/Homework/math/Prime_Numbers.txt")) { using (var fileStream = File....

This uses the Dropbox Python SDK to create a shared link for a file and also supplies a requested visibility and expiration in the settings: import datetime import dropbox dbx = dropbox.Dropbox("<ACCESS_TOKEN>") expires = datetime.datetime.now() + datetime.timedelta(days=30...

#include <stdio.h> #include <string.h> int main(void) { /* Always ensure that your string is large enough to contain the characters * and a terminating NUL character ('\0')! */ char mystring[10]; /* Copy "foo" into `mystring`, until a NUL character is en...

int* foo(int bar) { int baz = 6; baz += bar; return &baz; /* (&baz) copied to new memory location outside of foo. */ } /* (1) The lifetime of baz and bar end here as they have automatic storage * duration (local variables), thus the returned pointer is not valid! */ ...

Starting with a given list a: a = [1, 2, 3, 4, 5] append(value) – appends a new element to the end of the list. # Append values 6, 7, and 7 to the list a.append(6) a.append(7) a.append(7) # a: [1, 2, 3, 4, 5, 6, 7, 7] # Append another list b = [8, 9] a.append(b) # a: [1, 2, 3, 4, ...

int x = 0; int y = 5 / x; /* integer division */ or double x = 0.0; double y = 5.0 / x; /* floating point division */ or int x = 0; int y = 5 % x; /* modulo operation */ For the second line in each example, where the value of the second operand (x) is zero, the behaviour is undefine...

Note: The width and height attributes are not deprecated on images and never have been. Their use has been made much stricter though. The dimensions of an image can be specified using the width and height attributes of the image tag: <img src="images/200x200-img.png" width="2...

Basics The Reflection API allows one to check the class structure of the code at runtime and invoke code dynamically. This is very powerful, but it is also dangerous since the compiler is not able to statically determine whether dynamic invocations are valid. A simple example would be to get the p...