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C++17 C++17 introduces std::string_view, which is simply a non-owning range of const chars, implementable as either a pair of pointers or a pointer and a length. It is a superior parameter type for functions that requires non-modifiable string data. Before C++17, there were three options for this: ...

This example shows how to use the default logging api. import java.util.logging.Level; import java.util.logging.Logger; public class MyClass { // retrieve the logger for the current class private static final Logger LOG = Logger.getLogger(MyClass.class.getName()); pub...

One of the more popular .NET providers for Postgresql is Npgsql, which is ADO.NET compatible and is used nearly identically as other .NET database providers. A typical query is performed by creating a command, binding parameters, and then executing the command. In C#: var connString = "Host=m...

Given a JList like JList myList = new JList(items); the selected items in the list can be modified through the ListSelectionModel of the JList: ListSelectionModel sm = myList.getSelectionModel(); sm.clearSelection(); // clears the selection sm.setSelectionInterval(inde...

package { import flash.events.EventDispatcher; public class AbstractDispatcher extends EventDispatcher { public function AbstractDispatcher(target:IEventDispatcher = null) { super(target); } } } To dispatch an event on an instance: var dispatcher:AbstractDispatcher =...

The following example listens to window.onerror event and uses an image beacon technique to send the information through the GET parameters of an URL. var hasLoggedOnce = false; // Some browsers (at least Firefox) don't report line and column numbers // when event is handled through window.addE...

List doesn't support "random access", which means it takes more work to get, say, the fifth element from the list than the first element, and as a result there's no List.get nth list function. One has to go all the way from the beginning (1 -> 2 -> 3 -> 4 -> 5). If you need ra...

Using random.seed: np.random.seed(0) np.random.rand(5) # Out: array([ 0.5488135 , 0.71518937, 0.60276338, 0.54488318, 0.4236548 ]) By creating a random number generator object: prng = np.random.RandomState(0) prng.rand(5) # Out: array([ 0.5488135 , 0.71518937, 0.60276338, 0.54488318,...

The following method computes the Nth Fibonacci number using recursion. public int fib(final int n) { if (n > 2) { return fib(n - 2) + fib(n - 1); } return 1; } The method implements a base case (n <= 2) and a recursive case (n>2). This illustrates the use of re...

iex([email protected])> Node.list [:"[email protected]"]

Start two named nodes in two terminal windows: >iex --name [email protected] iex([email protected])> >iex --name [email protected] iex([email protected])> Connect two nodes by instructing one node to connect: iex([email protected])> Node.connect :"[email protected]" true The two n...

By recursion let rec sumTotal list = match list with | [] -> 0 // empty list -> return 0 | head :: tail -> head + sumTotal tail The above example says: "Look at the list, is it empty? return 0. Otherwise it is a non-empty list. So it could be [1], [1; 2], [1; 2; 3] ...

The * operator can be used to unpack variables and arrays so that they can be passed as individual arguments to a method. This can be used to wrap a single object in an Array if it is not already: def wrap_in_array(value) [*value] end wrap_in_array(1) #> [1] wrap_in_array([1, 2, 3]) ...

The Python Standard Library includes an interactive debugging library called pdb. pdb has extensive capabilities, the most commonly used being the ability to 'step-through' a program. To immediately enter into step-through debugging use: python -m pdb <my_file.py> This will start the debu...

The simple answer is that you cannot do this. Once an array has been created, its size cannot be changed. Instead, an array can only be "resized" by creating a new array with the appropriate size and copying the elements from the existing array to the new one. String[] listOfCities = ne...

The unary plus (+) precedes its operand and evaluates to its operand. It attempts to convert the operand to a number, if it isn't already. Syntax: +expression Returns: a Number. Description The unary plus (+) operator is the fastest (and preferred) method of converting something into a n...

The delete operator deletes a property from an object. Syntax: delete object.property delete object['property'] Returns: If deletion is successful, or the property did not exist: true If the property to be deleted is an own non-configurable property (can't be deleted): false in non...

The typeof operator returns the data type of the unevaluated operand as a string. Syntax: typeof operand Returns: These are the possible return values from typeof: TypeReturn valueUndefined"undefined"Null"object"Boolean"boolean"Number"number"String&quot...

The void operator evaluates the given expression and then returns undefined. Syntax: void expression Returns: undefined Description The void operator is often used to obtain the undefined primitive value, by means of writing void 0 or void(0). Note that void is an operator, not a functio...

The unary negation (-) precedes its operand and negates it, after trying to convert it to number. Syntax: -expression Returns: a Number. Description The unary negation (-) can convert the same types / values as the unary plus (+) operator can. Values that can't be converted will evaluat...