Tutorial by Examples: r

Just like most other C-style languages, each statement is terminated with a semicolon. Also, a closing tag is used to terminate the last line of code of the PHP block. If the last line of PHP code ends with a semicolon, the closing tag is optional if there is no code following that final line of co...

C++14 Those following string user literals are declared in the namespace std::literals::string_literals, where both literals and string_literals are inline namespaces. Access to these operators can be gained with using namespace std::literals, using namespace std::string_literals, and using namespa...

Assertations mean that a condition should be checked and if it's false, it's an error. For static_assert(), this is done compile-time. template<typename T> T mul10(const T t) { static_assert( std::is_integral<T>::value, "mul10() only works for integral types" ); re...

A default constructor is a type of constructor that requires no parameters when called. It is named after the type it constructs and is a member function of it (as all constructors are). class C{ int i; public: // the default constructor definition C() : i(0){ // member initial...

A destructor is a function without arguments that is called when a user-defined object is about to be destroyed. It is named after the type it destructs with a ~ prefix. class C{ int* is; string s; public: C() : is( new int[10] ){ } ~C(){ // destructor definition ...

See below for a simple example of how to use a BackgroundWorker object to perform time-intensive operations in a background thread. You need to: Define a worker method that does the time-intensive work and call it from an event handler for the DoWork event of a BackgroundWorker. Start the execu...

See below for a simple example of how to use a Thread to do some time intensive stuff in a background process. public async void ProcessDataAsync() { // Start the time intensive method Thread t = new Thread(TimeintensiveMethod); // Control returns here before TimeintensiveMethod r...

Subscripts can be used to simplify retrieving and setting elements in an array. Given the following array NSArray *fruit = @[@"Apples", @"Bananas", @"Cherries"]; This line [fruit objectAtIndex: 1]; Can be replaced by fruit[1]; They can also be used to set an...

Subscripts can also be used with NSDictionary and NSMutableDictionary. The following code: NSMutableDictionary *myDictionary = [@{@"Foo": @"Bar"} mutableCopy]; [myDictionary setObject:@"Baz" forKey:@"Foo"]; NSLog(@"%@", [myDictionary objectForKey:...

You can add subscripting to your own classes by implementing the required methods. For indexed subscripting (like arrays): - (id)objectAtIndexedSubscript:(NSUInteger)idx - (void)setObject:(id)obj atIndexedSubscript:(NSUInteger)idx For keyed subscripting (like dictionaries): - (id)objectForKey...

In PCRE, matched groups used for backreferences before a recursion are kept in the recursion. But after the recursion they all reset to what they were before entering it. In other words, matched groups in the recursion are all forgotten. For example: (?J)(?(DEFINE)(\g{a}(?<a>b)\g{a}))(?<a...

In PCRE, it doesn't trackback after the first match for a recursion is found. So (?(DEFINE)(aaa|aa|a))(?1)ab doesn't match aab because after it matched aa in the recursion, it never try again to match only a.

the steps in this example will use the following project structure as a demonstration and we intend to export it to the "GHTuts" Repository [Note that the Repo doesn't exist yet on github] but leave the "SensitiveProject" without publish as it contains some passwords, keys, et...

Prerequisite steps: Install Java at your machine Visit neo4j website and click the link "Download Community Edition" or visit directly the download link. Unzip the .tar downloaded file in your home directory Start Neo4j from console (headless, without web server) Visit the sub-d...

C++14 Those following complex user literals are declared in the namespace std::literals::complex_literals, where both literals and complex_literals are inline namespaces. Access to these operators can be gained with using namespace std::literals, using namespace std::complex_literals, and using nam...

The common idiom for loading shared library files in Java is the following : public class ClassWithNativeMethods { static { System.loadLibrary("Example"); } public native void someNativeMethod(String arg); ... Calls to System.loadLibrary are almost always...

Quite often you have a file which was edited within DOS or Windows and you are viewing it under UNIX. This can look like the following when you view the file with vi. First line of file^M Next Line^M And another^M If you wish to remove the ^M, it can be that you delete each ^M by hand. Alter...

Timers are used to perform tasks at specific intervals of time (Do X every Y seconds) Below is an example of creating a new instance of a Timer. NOTE: This applies to Timers using WinForms. If using WPF, you may want to look into DispatcherTimer using System.Windows.Forms; //Timers use the Wi...

All actions performed in a timer are handled in the "Tick" event. public partial class Form1 : Form { Timer myTimer = new Timer(); public Form1() { InitializeComponent(); myTimer.Tick += myTimer_Tick; //assign the event handler named "myT...

public partial class Form1 : Form { Timer myTimer = new Timer(); int timeLeft = 10; public Form1() { InitializeComponent(); //set properties for the Timer myTimer.Interval = 1000; myTimer.Enabled = tru...