Tutorial by Examples: an

An interface is declared like a class, but without access modifiers (public, private, ...). Also, no definitions are allowed, so variables and constants can't be used. Interfaces should always have an Unique Identifier, which can be generated by pressing Ctrl + Shift + G. IRepository = interface ...

Interfaces can inherit from each other, exactly like classes do, too. An implementing class thus has to implement functions of the interface and all base interfaces. This way, however, the compiler doesn't know that the implenting class also implements the base interface, it only knows of the interf...

Get a list of all jobs in the current session: Get-Job Waiting on a job to finish before getting the result: $job | Wait-job | Receive-Job Timeout a job if it runs too long (10 seconds in this example) $job | Wait-job -Timeout 10 Stopping a job (completes all tasks that are pending in t...

When using the DllImport attribute you have to know the correct dll and method name at compile time. If you want to be more flexible and decide at runtime which dll and methods to load, you can use the Windows API methods LoadLibrary(), GetProcAddress() and FreeLibrary(). This can be helpful if the ...

:autocmd BufWritePost * if &diff | diffupdate | endif

Get NSData from Hexadecimal String + (NSData *)dataFromHexString:(NSString *)string { string = [string lowercaseString]; NSMutableData *data= [NSMutableData new]; unsigned char whole_byte; char byte_chars[3] = {'\0','\0','\0'}; int i = 0; int length = (int) string.len...

A Semantic Model offers a deeper level of interpretation and insight of code compare to a syntax tree. Where syntax trees can tell the names of variables, semantic models also give the type and all references. Syntax trees notice method calls, but semantic models give references to the precise locat...

Often times, it is helpful to evaluate multiple expressions and to return the result from the first or second form rather than the last. This is easy to accomplish using let and, for instance: (let ((form1-result form1)) form2 form3 ;; ... form-n-1 form-n form1-result) Because...

Node Version Manager (nvm) greatly simplifies the management of Node.js versions, their installation, and removes the need for sudo when dealing with packages (e.g. npm install ...). Fish Shell (fish) "is a smart and user-friendly command line shell for OS X, Linux, and the rest of the family&...

Square Root Use Math.sqrt() to find the square root of a number Math.sqrt(16) #=> 4 Cube Root To find the cube root of a number, use the Math.cbrt() function 6 Math.cbrt(27) #=> 3 Finding nth-roots To find the nth-root, use the Math.pow() function and pass in a fractional expo...

Every Windows Phone project contains App.cs class: public sealed partial class App : Application This class is your global application context. General Application class usage: App entry point, particularly for various activation contracts. Application lifecycle management. Application g...

When I first started managing the keyboard I would use separate Notifications in each ViewController. Notification Method (Using NSNotification): class ViewController: UIViewController { override func viewDidLoad() { super.viewDidLoad() NSNotificationCenter.defaultCenter().a...

In most scripting languages, if a function call fails, it may throw an exception and stop execution of the program. Bash commands do not have exceptions, but they do have exit codes. A non-zero exit code signals failure, however, a non-zero exit code will not stop execution of the program. This can...

The behaviour of virtual functions in constructors and destructors is often confusing when first encountered. #include <iostream> using namespace std; class base { public: base() { f("base constructor"); } ~base() { f("base destructor"); } virtual co...

Principal Component Analysis finds sequences of linear combinations of the features. The first linear combination maximizes the variance of the features (subject to a unit constraint). Each of the following linear combinations maximizes the variance of the features in the subspace orthogonal to that...

Mage::app()->removeCache($cacheId); Flush all Magento cache entries Mage::app()->cleanCache() or: Mage::app()->getCacheInstance()->flush();

The addition and multiplication have equivalents in this type algebra. They correspond to the tagged unions and product types. data Sum a b = A a | B b data Prod a b = Prod a b We can see how the number of inhabitants of every type corresponds to the operations of the algebra. Equivalently, we...

The auto keyword by itself represents a value type, similar to int or char. It can be modified with the const keyword and the & symbol to represent a const type or a reference type, respectively. These modifiers can be combined. In this example, s is a value type (its type will be inferred as s...

Usage Sometimes, you could have to debug code in another PhpStorm project, you have to update the configuration. PHP configuration In php.ini, edit file and put xdebug.remote_autostart = 1 PhpStorm configuration You also have to configure your IDE: In the phpStorm configuration, Max. sim...

Lets use the same code as above for this example. #include <iostream> void fail() { int *p1; int *p2(NULL); int *p3 = p1; if (p3) { std::cout << *p2 << std::endl; } } int main() { fail(); } First lets compile it g++ -g -o main m...