Tutorial by Examples: d

POSIX/IEEE Open Group Base Specification says: [2addr] s/BRE/replacement/flags Substitute the replacement string for instances of the BRE in the pattern space. Any character other than backslash or newline can be used instead of a slash to delimit the BRE and the replacement. Within the BRE a...

Types can represents various kind of things. It can be a single data, a set of data or a function. In F#, we can group the types into two categories.: F# types: // Functions let a = fun c -> c // Tuples let b = (0, "Foo") // Unit type let c = ignore // Records...

Encapsulation is a basic concept in OOP. It is about wrapping data and code as a single unit. In this case, it is a good practice to declare the variables as private and then access them through Getters and Setters to view and/or modify them. public class Sample { private String name; privat...

In order to ssh into a server your identity's public key has to be added to the list of trusted keys. Most commonly this is done per-user: ssh-copy-id -i ~/.ssh/<identity>.pub <user>@<hostname> Which can be also done manually: cat ~/.ssh/<identity>.pub | ssh <user>...

import javax.ws.rs.DELETE; import javax.ws.rs.GET; import javax.ws.rs.Path; import javax.ws.rs.Produces; import javax.ws.rs.core.Response; @Path("hello") public class HelloWorldResource { private String message = "Hello StackOverflow!"; @GET @Produces(&...

The following function is returning another function as its result which can be later assigned to a variable and called: func jediTrainer () -> ((String, Int) -> String) { func train(name: String, times: Int) -> (String) { return "\(name) has been trained in the Force \(times)...

import javax.ws.rs.FormParam; import javax.ws.rs.POST; import javax.ws.rs.Path; import javax.ws.rs.core.Response; @Path("hello") public class HelloWorldResource { @POST @Path("/receiveParams") public Response receiveHello(@FormParam("name") String ...

Often data comes in tables. Generally one can divide this tabular data in wide and long formats. In a wide format, each variable has its own column. PersonHeight [cm]Age [yr]Alison17820Bob17445Carl18231 However, sometimes it is more convenient to have a long format, in which all variables are in o...

The Oracle Java Style Guide states: Modifiers should not be written out when they are implicit. (See Modifiers in Oracle Official Code Standard for the context and a link to the actual Oracle document.) This style guidance applies particularly to interfaces. Let's consider the following code ...

In this exercise, we will generate four bootstrap linear regression models and combine the summaries of these models into a single data frame. library(broom) #* Create the bootstrap data sets BootData <- lapply(1:4, function(i) mtcars[sample(1:nrow(mtcars), ...

The degree of parallelism is the maximum number of concurrently executing tasks that will be used to process the query. var sequence = Enumerable.Range(1, 10000); var evenNumbers = sequence.AsParallel() .WithDegreeOfParallelism(4) .Where(x =&gt...

This example shows how PLINQ can be used to calculate the even numbers between 1 and 10,000 using multiple threads. Order will be maintained in the resulting list, however keep in mind that AsOrdered may hurt performance for a large numbers of elements, so un-ordered processing is preferred when pos...

Ordered sequences may hurt performance when dealing with a large number of elements. To mitigate this, it's possible to call AsUnordered when the sequence order is no longer necessary. var sequence = Enumerable.Range(1, 10000).Select(x => -1 * x); // -1, -2, ... var evenNumbers = sequence.AsPar...

Derives from Object Key members public Dispatcher Dispatcher { get; } Summary Most objects in WPF derive from DispatcherObject, which provides the basic constructs for dealing with concurrency and threading. Such objects are associated with a Dispatcher. Only the thread that the Dispatcher w...

Derives from DispatcherObject Key members public object GetValue(DependencyProperty dp); public void SetValue(DependencyProperty dp, object value); Summary Classes derived from DependencyObject participate in the dependency property system, which includes registering dependency properties ...

A typical use case for SpriteKit is where the SKView fills the whole screen. To do this in Xcode's Interface Builder, first create a normal ViewController, then select the contained view and change its Class from UIView to SKView: Within the code for the View Controller, in the viewDidLoad metho...

The power of idling resources lies in not having to wait for some app's processing (networking, calculations, animations, etc.) to finish with sleep(), which brings flakiness and/or prolongs the tests run. The official documentation can be found here. Implementation There are three things that you...

Like in many other languages, Python uses the % operator for calculating modulus. 3 % 4 # 3 10 % 2 # 0 6 % 4 # 2 Or by using the operator module: import operator operator.mod(3 , 4) # 3 operator.mod(10 , 2) # 0 operator.mod(6 , 4) # 2 You can also use negative nu...

This is the basic HTML file that can be used as a boilerplate when starting a project. This boilerplate uses orbit controls with damping (camera that can move around an object with deceleration effect) and creates a spinning cube. <!DOCTYPE html> <html> <head> <t...

public function drawDisplayObjectUsingBounds(source:DisplayObject):BitmapData { var bitmapData:BitmapData;//declare a BitmapData var bounds:Rectangle = source.getBounds(source);//get the source object actual size //round bounds to integer pixel values (to aviod 1px str...