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You can open the VB editor in any of the Microsoft Office applications by pressing Alt+F11 or going to the Developer tab and clicking on the "Visual Basic" button. If you don't see the Developer tab in the Ribbon, check if this is enabled. By default the Developer tab is disabled. To enab...

Different data types for error/success def getPersonFromWebService(url: String): Either[String, Person] = { val response = webServiceClient.get(url) response.webService.status match { case 200 => { val person = parsePerson(response) if(!isVali...

What is recursion: In general, recursion is when a function invokes itself, either directly or indirectly. For example: // This method calls itself "infinitely" public void useless() { useless(); // method calls itself (directly) } Conditions for applying recursion to a probl...

To make a rounded UIView, specify a cornerRadius for the view's layer. This also applies any class which inherits from UIView, such as UIImageView. Programmatically Swift Code someImageView.layoutIfNeeded() someImageView.clipsToBounds = true someImageView.layer.cornerRadius = 10 Objective-C...

In this example, we will look at a method for returning the last non-empty row in a column for a data set. This method will work regardless of empty regions within the data set. However caution should be used if merged cells are involved, as the End method will be "stopped" against a mer...

All Java exceptions are instances of classes in the Exception class hierarchy. This can be represented as follows: java.lang.Throwable - This is the base class for all exception classes. Its methods and constructors implement a range of functionality common to all exceptions. java.lang.Excep...

A context manager is an object that is notified when a context (a block of code) starts and ends. You commonly use one with the with statement. It takes care of the notifying. For example, file objects are context managers. When a context ends, the file object is closed automatically: open_file = ...

enum MyEnum { One, Two, Three } foreach(MyEnum e in Enum.GetValues(typeof(MyEnum))) Console.WriteLine(e); This will print: One Two Three

Substitutability is a principle in object-oriented programming introduced by Barbara Liskov in a 1987 conference keynote stating that, if class B is a subclass of class A, then wherever A is expected, B can be used instead: class A {...} class B extends A {...} public void method(A obj) {...} ...

You can set the timezone that will be used by Django in the settings.py file. Examples: TIME_ZONE = 'UTC' # use this, whenever possible TIME_ZONE = 'Europe/Berlin' TIME_ZONE = 'Etc/GMT+1' Here is the list of valid timezones When running in a Windows environment this must be set to the same a...

If the items in your RecyclerView load data from the network (commonly images) or carry out other processing, that can take a significant amount of time and you may end up with items on-screen but not fully loaded. To avoid this you can extend the existing LinearLayoutManager to preload a number of...

This progam uses VCL, the default UI components library of Delphi, to print "Hello World" into a message box. The VCL wrapps most of the commonly used WinAPI components. This way, they can be used much easier, e.g. without the need to work with Window Handles. To include a dependency (lik...

Objective-C CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"position.x"]; animation.fromValue = @0; animation.toValue = @320; animation.duration = 1; [_label.layer addAnimation:animation forKey:@"basic"]; Swift let animation = CAB...

XML is made of basic building blocks, which are: element text attributes comments processing instructions An element has angle brackets: <element/> <element>some content</element> An attribute appears in an opening element tag: <element attribute-name="...

The ternary operator is used for inline conditional expressions. It is best used in simple, concise operations that are easily read. The order of the arguments is different from many other languages (such as C, Ruby, Java, etc.), which may lead to bugs when people unfamiliar with Python's "s...

foo.h #ifndef FOO_DOT_H /* This is an "include guard" */ #define FOO_DOT_H /* prevents the file from being included twice. */ /* Including a header file twice causes all kinds */ /* of interesting problems.*/ /** * This is a functi...

The Clojure community puts a large emphasis on interactive development, so quite a lot of interaction with Clojure happens within a REPL (read-eval-print-loop). When you input an expression into it, Clojure reads it, evaluates it, and prints the result of the evaluation, all in a loop. You should b...

The function is_array() returns true if a variable is an array. $integer = 1337; $array = [1337, 42]; is_array($integer); // false is_array($array); // true You can type hint the array type in a function to enforce a parameter type; passing anything else will result in a fatal error. funct...

slice1 := []string{"!"} slice2 := []string{"Hello", "world"} slice := append(slice1, slice2...) Run in the Go Playground

package main import ( "fmt" "io/ioutil" ) func main() { files, err := ioutil.ReadDir(".") if err != nil { panic(err) } fmt.Println("Files and folders in the current directory:") for _, fileInfo := range fi...