Tutorial by Examples: re

PHP makes it easy to get data from your results and loop over it using a while statement. When it fails to get the next row, it returns false, and your loop ends. These examples work with mysqli_fetch_assoc - Associative array with column names as keys mysqli_fetch_object - stdClass object with ...

The return statement in Bash doesn't return a value like C-functions, instead it exits the function with a return status. You can think of it as the exit status of that function. If you want to return a value from the function then send the value to stdout like this: fun() { local var="S...

If you want to mimic HTML form POST action, you can use cURL. // POST data in array $post = [ 'a' => 'apple', 'b' => 'banana' ]; // Create a new cURL resource with URL to POST $ch = curl_init('http://www.example.com'); // We set parameter CURLOPT_RETURNTRANSFER to read outp...

Before C++17, having pointers with a value of nullptr commonly represented the absence of a value. This is a good solution for large objects that have been dynamically allocated and are already managed by pointers. However, this solution does not work well for small or primitive types such as int, w...

Before C++17, a function typically represented failure in one of several ways: A null pointer was returned. e.g. Calling a function Delegate *App::get_delegate() on an App instance that did not have a delegate would return nullptr. This is a good solution for objects that have been dynamicall...

In most examples, the class naming convention is used to define an Aurelia Custom Element. However, Aurelia also provides a decorator that can be used to decorate a class. The class is again treated as a custom element by Aurelia then. The value supplied to the decorator becomes the name of the cus...

Usually data sent in a POST request is structured key/value pairs with a MIME type of application/x-www-form-urlencoded. However many applications such as web services require raw data, often in XML or JSON format, to be sent instead. This data can be read using one of two methods. php://input is a...

This illustrates that union members shares memory and that struct members does not share memory. #include <stdio.h> #include <string.h> union My_Union { int variable_1; int variable_2; }; struct My_Struct { int variable_1; int variable_2; }; int main (void) { ...

Some C implementations permit code to write to one member of a union type then read from another in order to perform a sort of reinterpreting cast (parsing the new type as the bit representation of the old one). It is important to note however, this is not permitted by the C standard current or pas...

To create a custom template we first need to create php file in a theme directory. You can name it almost any way you want. For this example we will create example.php One and only thing we need to define inside our example.php, to be recognized by WordPress as a template, is template name. We do t...

If targeting Flash Player 11+, the built-in removeChildren method is the best way to remove all children: removeChildren(); //a start and end index can be passed For legacy applications, the same can be accomplished with a loop: while (numChildren > 0) { removeChildAt(0); }

Enums in Swift are much more powerful than some of their counterparts in other languages, such as C. They share many features with classes and structs, such as defining initialisers, computed properties, instance methods, protocol conformances and extensions. protocol ChangesDirection { mutati...

package { import flash.events.TimerEvent; import flash.utils.Timer; public class CountdownTimer extends Timer { public var time:Number = 0; public function CountdownTimer(time:Number = Number.NEGATIVE_INFINITY, delay:Number = 1000) { super(delay, repeatCount); ...

Using functions that take in and execute closures can be extremely useful for sending a block of code to be executed elsewhere. We can start by allowing our function to take in an optional closure that will (in this case) return Void. func closedFunc(block: (()->Void)? = nil) { print("...

// RawRepresentable has an associatedType RawValue. // For this struct, we will make the compiler infer the type // by implementing the rawValue variable with a type of String // // Compiler infers RawValue = String without needing typealias // struct NotificationName: RawRepresentable { ...

Select the .xcdatamodeld file. You will notice you have no entities. You will have to create one yourself. At the bottom of Xcode you will notice a button that says "Add Entity" click it and you will have a new entity for you to work with on the project. In this step there are ...

We define the type of boolean expressions whose atoms are identified by strings as type expr = | Atom of string | Not of expr | And of expr * expr | Or of expr * expr and can evaluate these expressions using an oracle : string -> bool giving the values of the atoms we find as follows: le...

Pattern matching can be used to deconstruct records. We illustrate this with a record type representing locations in a text file, e.g. the source code of a program. type location = { filename : string; line: int; column: int; offset: int; } A value x of type location can be deconstr...

We prepare a file called reverser.ml with the following contents: let acc = ref [] in try while true do acc := read_line () :: !acc; done with End_of_file -> print_string (String.concat "\n" !acc) We then compile our program using ...

The List.fold_left and List.fold_right functions are higher-order functions that implement the outer logic of list aggregation. Aggregating a list, sometimes also referred to as reducing a list, means computing a value derived from the sequential inspection of all items in that list. The documenta...