PHP supports the set of trigonometry functions, the PHP’s mathematical library also includes the exponential and logarithmic functions.
Often it’s useful to consider an array in reverse order. The array_reverse( ) function creates a new array by reversing the elements from a source array.
PHP generators are a powerful feature that allow you to create iterators without writing a class that implements the Iterator interface.
FTP is not a secure protocol and should not be used. PHP also offers SSH-based functions that helps you to create a secure FTP (SFTP) connection to your web server.
PHP comes with built-in support for FTP and a special set of functions that implement the complete FTP functionality defined in the associated Request for Comment (RFC).
If you have a web server and you want to check periodically if it didn’t crash again. Just create a PHP script, open a socket to the server with fsockopen() function, and wait. After the time specified in the $timeout parameter has elapsed, you know if the server is online or offline.
PHP can communicate with other servers using sockets. Sockets allow data exchange between processes on the same or different servers. PHP uses the fsockopen() function to open a socket connection to a web server.
As mentioned previously, current Web Services almost always use WSDL (Web Services Description Language) to describe the operations and parameters of your service. Writing WSDL files manually is a real pain and error-prone, but most serious Web Services implementations for PHP can automatically create WSDL.
How to create a SOAP service in PHP. You will write code in two files: a server file and a client file. The server file defines the functions that the service can perform, and the client file calls those functions and displays the results.
A web service is an interfaceless application that can be called to process information. In PHP, a web service can provide the functionality remotely on a web server.