Tutorial by Examples: io

The library CL-PPCRE provides the function split which allows us to split strings in substrings that match a regular expression, discarding the parts of the string that do not. (cl-ppcre:split "\\." "127.0.0.1") ;; => ("127" "0" "0" "1&quot...

A Broadcast receiver is an Android component which allows you to register for system or application events. A receiver can be registered via the AndroidManifest.xml file or dynamically via the Context.registerReceiver() method. public class MyReceiver extends BroadcastReceiver { @Override ...

To add a method to a button, first create an action method: Objective-C -(void)someButtonAction:(id)sender { // sender is the object that was tapped, in this case its the button. NSLog(@"Button is tapped"); } Swift func someButtonAction() { print("Button is tapped...

To find all the files of a certain extension within the current path you can use the following find syntax. It works by making use of bash's built-in glob construct to match all the names having the .extension. find /directory/to/search -maxdepth 1 -type f -name "*.extension" To find ...

Subclass UINavigationController and then override these methods: In Objective-C: - (UIStatusBarStyle)preferredStatusBarStyle { return UIStatusBarStyleLightContent; } In Swift: override func preferredStatusBarStyle() -> UIStatusBarStyle { return .lightContent } Alternativel...

Note that you cannot overload a function based on its return type. For example: // WRONG CODE std::string getValue() { return "hello"; } int getValue() { return 0; } int x = getValue(); This will cause a compilation error as the compiler will not be able to work out wh...

Since C# 6.0 exceptions can be filtered using the when operator. This is similar to using a simple if but does not unwind the stack if the condition inside the when is not met. Example try { // ... } catch (Exception e) when (e.InnerException != null) // Any condition can go in here. { ...

Within a catch block the throw keyword can be used on its own, without specifying an exception value, to rethrow the exception which was just caught. Rethrowing an exception allows the original exception to continue up the exception handling chain, preserving its call stack or associated data: try...

A Sub is a procedure that performs a specific task but does not return a specific value. Sub ProcedureName ([argument_list]) [statements] End Sub If no access modifier is specified, a procedure is Public by default. A Function is a procedure that is given data and returns a value, ideally...

SRXMPPDemo Download the example and all the classes here - https://github.com/SahebRoy92/SRXMPPDemo A demo on XMPP in Objective C, with various simple and complex features implemented in it. All the features of XMPP is done by "in band" xmpp functions. Few features this project contains...

Using the Array::new constructor, your can initialize an array with a given size and a new array in each of its slots. The inner arrays can also be given a size and and initial value. For instance, to create a 3x4 array of zeros: array = Array.new(3) { Array.new(4) { 0 } } The array generated a...

Define your class that will represent your custom error. public class ErrorDto { public int Code { get; set; } public string Message { get; set; } // other fields public override string ToString() { return JsonConvert.SerializeObject(this); } } Then put nex...

The class we are going to test is: public class Service{ private Collaborator collaborator; public Service(Collaborator collaborator){ this.collaborator = collaborator; } public String performService(String input){ return collaborator.transformS...

Enumerable is the most popular module in Ruby. Its purpose is to provide you with iterable methods like map, select, reduce, etc. Classes that use Enumerable include Array, Hash, Range. To use it, you have to include Enumerable and implement each. class NaturalNumbers include Enumerable de...

The core concepts of RxJava are its Observables and Subscribers. An Observable emits objects, while a Subscriber consumes them. Observable Observable is a class that implements the reactive design pattern. These Observables provide methods that allow consumers to subscribe to event changes. The ev...

Java-like enumerations can be created by extending Enumeration. object WeekDays extends Enumeration { val Mon, Tue, Wed, Thu, Fri, Sat, Sun = Value } def isWeekend(day: WeekDays.Value): Boolean = day match { case WeekDays.Sat | WeekDays.Sun => true case _ => false } isWeekend...

Functions can either be named or unnamed (anonymous functions): var namedSum = function sum (a, b) { // named return a + b; } var anonSum = function (a, b) { // anonymous return a + b; } namedSum(1, 3); anonSum(1, 3); 4 4 But their names are private to their own scope: ...

To avoid verbose null checking, the ?. operator has been introduced in the language. The old verbose syntax: If myObject IsNot Nothing AndAlso myObject.Value >= 10 Then Can be now replaced by the concise: If myObject?.Value >= 10 Then The ? operator is particularly powerful when you...

This new feature makes the string concatenation more readable. This syntax will be compiled to its equivalent String.Format call. Without string interpolation: String.Format("Hello, {0}", name) With string interpolation: $"Hello, {name}" The two lines are equivalent and ...

Dim array() As Integer = {2, 0, 1, 6} ''Initialize an array of four Integers. Dim strings() As String = {"this", "is", "an", "array"} ''Initialize an array of four Strings. Dim floats() As Single = {56.2, 55.633, 1.2, 5.7743, 22.345} ...