Tutorial by Examples: ar

Template parameter deduction for constructors

Prior to C++17, template deduction cannot deduce the class type for you in a constructor. It must be explicitly specified. Sometimes, however, these types can be very cumbersome or (in the case of lambdas) impossible to name, so we got a proliferation of type factories (like make_pair(), make_tuple(...

C++ • type deduction

Add a Remote Repository

To add a remote, use git remote add in the root of your local repository. For adding a remote Git repository <url> as an easy short name <name> use git remote add <name> <url> The command git fetch <name> can then be used to create and update remote-tracking branch...

Git • Git Remote

Rename a Remote Repository

Rename the remote named <old> to <new>. All remote-tracking branches and configuration settings for the remote are updated. To rename a remote branch name dev to dev1 : git remote rename dev dev1

Git • Git Remote

Remove a Remote Repository

Remove the remote named <name>. All remote-tracking branches and configuration settings for the remote are removed. To remove a remote repository dev: git remote rm dev

Git • Git Remote

Creating an array of sequential numbers

LINQ provides a method that makes it easy to create a collection filled with sequential numbers. For example, you can declare an array which contains the integers between 1 and 100. The Enumerable.Range method allows us to create sequence of integer numbers from a specified start position and a num...

C# Language • Arrays

Creating particles with CAEmitterLayer

The CAEmitterLayer class provides a particle emitter system for Core Animation. The particles are defined by instances of CAEmitterCell. The particles are drawn above the layer’s background color and border. var emitter = CAEmitterLayer() emitter.emitterPosition = CGPoin...

iOS • CALayer

Character literals

Character literals are a special type of integer literals that are used to represent one character. They are enclosed in single quotes, e.g. 'a' and have the type int. The value of the literal is an integer value according to the machine's character set. They do not allow suffixes. The L prefix bef...

C Language • Literals for numbers, characters and strings

Accessing Parameters

When executing a Bash script, parameters passed into the script are named in accordance to their position: $1 is the name of the first parameter, $2 is the name of the second parameter, and so on. A missing parameter simply evaluates to an empty string. Checking for the existence of a parameter can...

Bash • Scripting with Parameters

IComparable as an Example of Implementing an Interface

Interfaces can seem abstract until you seem them in practice. The IComparable and IComparable<T> are great examples of why interfaces can be helpful to us. Let's say that in a program for a online store, we have a variety of items you can buy. Each item has a name, an ID number, and a price. ...

C# Language • Interfaces

Parsing JavaScript Generated Page with Jsoup and HtmUnit

page.html - source code <html> <head> <script src="loadData.js"></script> </head> <body onLoad="loadData()"> <div class="container"> <table id="data" border="1"> <...

Jsoup • Parsing Javascript Generated Pages

Pitfall: using == to compare strings

A common mistake for Java beginners is to use the == operator to test if two strings are equal. For example: public class Hello { public static void main(String[] args) { if (args.length > 0) { if (args[0] == "hello") { System.out.println(&q...

Java Language • Common Java Pitfalls

Creating zip archive from directory

System.IO.Compression.ZipFile.CreateFromDirectory("myfolder", "archive.zip") Create archive.zip file containing files which are in myfolder. In example paths are relative to program working directory. You can specify absolute paths.

Visual Basic .NET Language • File/Folder Compression

Extracting zip archive to directory

System.IO.Compression.ZipFile.ExtractToDirectory("archive.zip", "myfolder") Extracts archive.zip to myfolder directory. In example paths are relative to program working directory. You can specify absolute paths.

Visual Basic .NET Language • File/Folder Compression

Create zip archive dynamicaly

' Create filestream to file Using fileStream = New IO.FileStream("archive.zip", IO.FileMode.Create) ' open zip archive from stream Using archive = New System.IO.Compression.ZipArchive(fileStream, IO.Compression.ZipArchiveMode.Create) ' create file_in_archive.txt in arch...

Visual Basic .NET Language • File/Folder Compression

Dictionaries are unordered

You might expect a Python dictionary to be sorted by keys like, for example, a C++ std::map, but this is not the case: myDict = {'first': 1, 'second': 2, 'third': 3} print(myDict) # Out: {'first': 1, 'second': 2, 'third': 3} print([k for k in myDict]) # Out: ['second', 'third', 'first'] Py...

Python Language • Common Pitfalls

RecordWildCards

See RecordWildCards

Haskell Language • Common GHC Language Extensions

Verifying Arguments with ArgumentMatcher

Mockito provides a Matcher<T> interface along with an abstract ArgumentMatcher<T> class to verify arguments. It uses a different approach to the same use-case than the ArgumentCaptor. Additionally the ArgumentMatcher can be used in mocking too. Both use-cases make use of the Mockito.argT...

mockito • Getting started with mockito

Before vs. After Middleware

An example of "before" middleware would be as follows: <?php namespace App\Http\Middleware; use Closure; class BeforeMiddleware { public function handle($request, Closure $next) { // Perform action return $next($request); } } while &quot...

Laravel • Middleware

Using Deref and AsRef for function arguments

For functions that need to take a collection of objects, slices are usually a good choice: fn work_on_bytes(slice: &[u8]) {} Because Vec<T> and arrays [T; N] implement Deref<Target=[T]>, they can be easily coerced to a slice: let vec = Vec::new(); work_on_bytes(&vec); le...

Rust • Auto-dereferencing

Enable ALV Toolbar Functionality

The following method call enables usage of many advanced features such as sorting, filtering, and exporting data. alv->get_functions( )->set_all( ).

ABAP • ABAP GRID List Viewer (ALV)