Tutorial by Examples: ga

The arrayref for @foo is \@foo. This is handy if you need to pass an array and other things to a subroutine. Passing @foo is like passing multiple scalars. But passing \@foo is a single scalar. Inside the subroutine: xyz(\@foo, 123); ... sub xyz { my ($arr, $etc) = @_; print $arr-&g...

Objective C NSURL *url = [NSURL URLWithString:@"YOUR URL"]; AVPlayer *player = [AVPlayer playerWithURL:videoURL]; AVPlayerLayer *playerLayer = [AVPlayerLayer playerLayerWithPlayer:player]; playerLayer.frame = self.view.bounds; [self.view.layer addSublayer:playerLayer]; [player play];...

NSMutableDictionary *attributesDictionary = [NSMutableDictionary dictionary]; [attributesDictionary setObject:[UIFont systemFontOfSize:14] forKey:NSFontAttributeName]; //[attributesDictionary setObject:[UIColor redColor] forKey:NSForegroundColorAttributeName]; NSMutableAttributedString *attri...

Task that return a value has return type of Task< TResult > where TResult is the type of value that needs to be returned. You can query the outcome of a Task by its Result property. Task<int> t = Task.Run(() => { int sum = 0; for(int i = 0; i < 500; i++) ...

lessc [options] <source> [destination] The above command is used to compile Less files in the command line. Options are the various settings that the compiler should use either during compilation or after compilation. Options include -x or --compress for compressing or minifying the output ...

If we have a Model as following, from django.db import models from django.contrib.auth.models import User class UserModuleProfile(models.Model): user = models.OneToOneField(User) expired = models.DateTimeField() admin = models.BooleanField(default=False) employee_id = models...

To view an browse Vaadin add-ons in the Directory, you must be registered to vaadin.com. After the initial discovery of artifact details, e.g. for download and usage, registration is not required. Also, the usage of add-ons in a Maven project is not IDE-specific and the same instructions apply. Fro...

Partial classes provide a clean way to separate core logic of your scripts from platform specific methods. Partial classes and methods are marked with the keyword partial. This signals the compiler to leave the class "open" and look in other files for the rest of the implementation. // E...

Import the class, which contains the method to be tested. Perform the operation with dummy data. Now compare the result of operation with expected result. - (void)testReverseString{ NSString *originalString = @"hi_my_name_is_siddharth"; NSString *reversedString = [self.someObject ...

- (void)testDoSomethingThatTakesSomeTime{ XCTestExpectation *completionExpectation = [self expectationWithDescription:@"Long method"]; [self.someObject doSomethingThatTakesSomeTimesWithCompletionBlock:^(NSString *result) { XCTAssertEqualObjects(@"result", result, @"Re...

public static async Task<WriteableBitmap> RenderUIElement(UIElement element) { var bitmap = new RenderTargetBitmap(); await bitmap.RenderAsync(element); var pixelBuffer = await bitmap.GetPixelsAsync(); var pixels = pixelBuffer.ToArray(); var writeableBitmap = new W...

The pipe (%>%) operator could be used in combination with dplyr functions. In this example we use the mtcars dataset (see help("mtcars") for more information) to show how to sumarize a data frame, and to add variables to the data with the result of the application of a function. librar...

Writing with roxygen2 roxygen2 is a package created by Hadley Wickham to facilitate documentation. It allows to include the documentation inside the R script, in lines starting by #'. The different parameters passed to the documentation start with an @, for example the creator of a package will by...

To open an app with defined URL scheme todolist://: Objective-C NSURL *myURL = [NSURL URLWithString:@"todolist://there/is/something/to/do"]; [[UIApplication sharedApplication] openURL:myURL]; Swift let stringURL = "todolist://there/is/something/to/do" if let url = NSURL(s...

A use case that comes across frequently, is creating a String from a stream, where the stream-items are separated by a certain character. The Collectors.joining() method can be used for this, like in the following example: Stream<String> fruitStream = Stream.of("apple", "banana...

Any attempt to modify a const object results in undefined behavior. This applies to const variables, members of const objects, and class members declared const. (However, a mutable member of a const object is not const.) Such an attempt can be made through const_cast: const int x = 123; const_cas...

You will need a domain name from a registrar. In the gh-pages branch of your project repository, or the main branch of your username.github.io repository, create a CNAME file with the contents www.yourdomain.com - the canonical domain. At your registrar's domain configuration page, point your doma...

$ fg %2 sleep 600 %2 specifies job no. 2. If fg is used without any arguments if brings the last process put in background to the foreground. $ fg %?sle sleep 500 ?sle refers to the baground process command containing "sle". If multiple background commands contain the string, it w...

To create a blank image, use the imagecreatetruecolor function: $img = imagecreatetruecolor($width, $height); $img is now a resource variable for an image resource with $widthx$height pixels. Note that width counts from left to right, and height counts from top to bottom. Image resources can al...

If you want to set some alias name to installed node version, do: nvm alias <name> <version> Similary to unalias, do: nvm unalias <name> A proper usecase would be, if you want to set some other version than stable version as default alias. default aliased versions are loade...