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You can use Optional Chaining in order to call a method, access a property or subscript an optional. This is done by placing a ? between the given optional variable and the given member (method, property or subscript). struct Foo { func doSomething() { print("Hello World!") ...

Here is a simple model that we will use to run a few test queries: class MyModel(models.Model): name = models.CharField(max_length=10) model_num = models.IntegerField() flag = models.NullBooleanField(default=False) Get a single model object where the id/pk is 4: (If there are no...

Install gunicorn pip install gunicorn From django project folder (same folder where manage.py resides), run the following command to run current django project with gunicorn gunicorn [projectname].wsgi:application -b 127.0.0.1:[port number] You can use the --env option to set the pat...

What’s a component? A component is basically a directive that uses a simpler configuration and that is suitable for a component-based architecture, which is what Angular 2 is all about. Think of a component as a widget: A piece of HTML code that you can reuse in several different places in y...

OptionSetType is a protocol designed to represent bit mask types where individual bits represent members of the set. A set of logical and/or functions enforce the proper syntax: struct Features : OptionSet { let rawValue : Int static let none = Features(rawValue: 0) static let feature0 = F...

The standard ADB configuration involves a USB connection to a physical device. If you prefer, you can switch over to TCP/IP mode, and connect ADB via WiFi instead. Not rooted device Get on the same network: Make sure your device and your computer are on the same network. Connect the...

You can create an ordered dictionary which will follow a determined order when iterating over the keys in the dictionary. Use OrderedDict from the collections module. This will always return the dictionary elements in the original insertion order when iterated over. from collections import Ordere...

The const keyword declares a global constant binding. const DEADBEEF: u64 = 0xDEADBEEF; fn main() { println("{:X}", DEADBEEF); } This outputs DEADBEEF

Get the current date. LocalDate.now() Get yesterday's date. LocalDate y = LocalDate.now().minusDays(1); Get tomorrow's date LocalDate t = LocalDate.now().plusDays(1); Get a specific date. LocalDate t = LocalDate.of(1974, 6, 2, 8, 30, 0, 0); In addition to the plus and minus methods, ...

Writing testable code is an important part of building a robust, maintainable, and agile project. Support for PHP's most widely used testing framework, PHPUnit, is built right into Laravel. PHPUnit is configured using the phpunit.xml file, which resides in the root directory of every new Laravel app...

function add(a, b) return a + b end -- creates a function called add, which returns the sum of it's two arguments Let's look at the syntax. First, we see a function keyword. Well, that's pretty descriptive. Next we see the add identifier; the name. We then see the arguments (a, b) these c...

Functions are only useful if we can call them. To call a function the following syntax is used: print("Hello, World!") We're calling the print function. Using the argument "Hello, World". As is obvious, this will print Hello, World to the output stream. The returned value is ...

Creating anonymous functions Anonymous functions are just like regular Lua functions, except they do not have a name. doThrice(function() print("Hello!") end) As you can see, the function is not assigned to any name like print or add. To create an anonymous function, all you hav...

Views, in an MVC pattern, contain the logic on how to present data to the user. In a web application, typically they are used to generate the HTML output that is sent back to users with each response. By default, views in Laravel are stored in the resources/views directory. A view can be called u...

function output = mymult(a, b) % MYMULT Multiply two numbers. % output = MYMULT(a, b) multiplies a and b. % % See also fft, foo, sin. % % For more information, see <a href="matlab:web('https://google.com')">Google</a>. output = a * b; end help mymult then p...

The padding property sets the padding space on all sides of an element. The padding area is the space between the content of the element and its border. Negative values are not allowed. You can specify a side individually: padding-top padding-right padding-bottom padding-left The following...

TODO: Maybe move the explanations to remarks and add examples separately FOOF In Common Lisp, there is a concept of Generalized References. They allow a programmer to setf values to various "places" as if they were variables. Macros that make use of this ability often have a F-postfix in...

json.Marshal from the package "encoding/json" encodes a value to JSON. The parameter is the value to encode. The returned values are an array of bytes representing the JSON-encoded input (on success), and an error (on failure). decodedValue := []string{"foo", "bar"} ...

json.Unmarshal from the package "encoding/json" decodes a JSON value into the value pointed by the given variable. The parameters are the value to decode in []bytes and a variable to use as a storage for the de-serialized value. The returned value is an error (on failure). encodedValue :...

After following the instructions above and installing Leiningen, start a new project by running: lein new <project-name> This will setup a Clojure project with the default Leiningen template within the <project-name> folder. There are several templates for Leiningen, which affect the...