Tutorial by Examples: d

Def: Final Keyword prevents child classes from overriding a method by prefixing the definition with final. If the class itself is being defined final then it cannot be extended Final Method class BaseClass { public function test() { echo "BaseClass::test() called\n"; } ...

The do operator iterates over a block of code until a conditional query equals false. The do-while loop can also be interrupted by a goto, return, break or throw statement. The syntax for the do keyword is: do { code block; } while( condition ); Example: int i = 0; do { Console.W...

The @ sign binds a variable to a name during a pattern match. The bound variable can either be the entire matched object or part of the matched object: sealed trait Shape case class Rectangle(height: Int, width: Int) extends Shape case class Circle(radius: Int) extends Shape case object Point ex...

The left hand operand for these operators must be a either a non-final variable or an element of an array. The right hand operand must be assignment compatible with the left hand operand. This means that either the types must be the same, or the right operand type must be convertible to the left o...

The R-Logo is a multilayer raster file (red, green, blue) library(raster) r <- stack("C:/Program Files/R/R-3.2.3/doc/html/logo.jpg") plot(r) The individual layers of the RasterStack object can be adressed by [[. plot(r[[1]])

Behavior Driven Development (BDD) testing style revolves around "given", "when" and "then" stages in tests. However, classical Mockito uses "when" word for "given" phase, and does not include other natural language constructions that can encompass B...

There is no simple way to obtain attributes from an interface, since classes does not inherit attributes from an interface. Whenever implementing an interface or overriding members in a derived class, you need to re-declare the attributes. So in the example below output would be True in all three c...

In this example our project name is "helloworld" which was created with stack new helloworld simple First we have to build the project with stack build and then we can run it with stack exec helloworld-exe

The code below implements a very simple complex number type for which the underlying field is automatically promoted, following the language's type promotion rules, under application of the four basic operators (+, -, *, and /) with a member of a different field (be it another complex<T> or so...

To take a photo, first we need to declare required permissions in AndroidManifest.xml. We need two permissions: Camera - to open camera app. If attribute required is set to true you will not be able to install this app if you don't have hardware camera. WRITE_EXTERNAL_STORAGE - This permission i...

ng-include allows you to delegate the control of one part of the page to a specific controller. You may want to do this because the complexity of that component is becoming such that you want to encapsulate all the logic in a dedicated controller. An example is: <div ng-include src=&q...

def foo(li=[]): li.append(1) print(li) foo([2]) # Out: [2, 1] foo([3]) # Out: [3, 1] This code behaves as expected, but what if we don't pass an argument? foo() # Out: [1] As expected... foo() # Out: [1, 1] Not as expected... This is because default arguments of function...

Consider the case of creating a nested list structure by multiplying: li = [[]] * 3 print(li) # Out: [[], [], []] At first glance we would think we have a list of containing 3 different nested lists. Let's try to append 1 to the first one: li[0].append(1) print(li) # Out: [[1], [1], [1]] ...

iex> [1, 2, 3] -- [1, 3] [2] -- removes the first occurrence of an item on the left list for each item on the right.

Use Conditionals via (syntax is in [brackets]): when [when:] Task: - name: run if operating system is debian command: echo "I am a Debian Computer" when: ansible_os_family == "Debian" loops [with_items:] loops [with_dicts:] Custom Facts [ wh...

Common use when: ansible_os_family == "CentOS" when: ansible_os_family == "Redhat" when: ansible_os_family == "Darwin" when: ansible_os_family == "Debian" when: ansible_os_family == "Windows" All Lists based on discuss here http://comments...

Basic Usage Use the when condition to control whether a task or role runs or is skipped. This is normally used to change play behavior based on facts from the destination system. Consider this playbook: - hosts: all tasks: - include: Ubuntu.yml when: ansible_os_family == "Ubunt...

Ordering the results and setting a limit can easily be achieved with 2 additional lines added to the chain, like so: $db = JFactory::getDbo(); $query = $db->getQuery(true); $query->select('*') ->from('#__users') ->where('username = '. $db->q('John')) ->ord...

Directives can be used to build reusable components. Here is an example of a "user box" component: userBox.js angular.module('simpleDirective', []).directive('userBox', function() { return { scope: { username: '=username', reputation: '=reputation' }, ...

Behaviours are a list of functions specifications that another module can implement. They are similar to interfaces in other languages. Here’s an example behaviour: defmodule Parser do @callback parse(String.t) :: any @callback extensions() :: [String.t] end And a module that implements ...