Category: 13. Advanced

In PHP7, a new IntlChar class has been introduced. It provides access to a number of utility methods that can be used to access information about Unicode characters. There are a number of static methods and constants in Intl class. They adhere closely to the names and behavior used by the underlying ICU (International Components…

In PHP, the built-in function unserialize() is available from PHP version 4 onwards. With PHP 7, a provision to pass a list of allowed classes has been added. This allows the untrusted source to be filtered out. The unserialze() function unserializes the data from only the trusted classes. In PHP, serialization means generation of a…

In PHP, a closure is an anonymous function that has access to the variables in the scope in which it was created, even after that scope has closed. You need to specify use keyword in it. Closures are objects that encapsulate the function code and the scope in which they were created. With PHP 7, a new closure::call() method…

PHP doesn’t provide any built-in function with which you can swap or interchange values of two variables. However, there are a few techniques which you can use to perform the swap. One of the most straightforward approaches is to use a third variable as a temporary place holder to facilitate swapping. Using the arithmetic operators…

In PHP, the header() function is used to send an “Authentication Required” message to the client browser causing it to pop up a Username/Password input window. In fact header() allows you to send any raw HTTP header. The string parameter is passed to the header() function. For example It is used to figure out the…

PHP’s library of built-in function includes a category of functions that deal with invoking operating system utilities and external programs from within the PHP code. In this chapter, we shall discuss the PHP functions used to perform system calls. The system() Function The system() function is similar to the system() function in C that it…

PHP defines NULL as one of its special data types. It indicates that a certain variable has not been assigned a value any specific data type. It is a built-in constant in PHP and is used to indicate the intentional absence of any object or value. A variable can be explicitly assigned NULL or its…

Early versions of PHP included mcrypt extension, that provided encryption/decryption capabilities. Due to lack of maintenance, the mycrypt extension has been deprecated and removed from PHP 7.2 version onwards. PHP now includes OpenSSL library that has an extensive functionality to support encryption and decryption features. OpenSSL supports various encryption algorithms such as AES (Advanced Encryption…

The term “hashing” represents a technique of encrypting data (specially a text) to obtain a fixed-length value. PHP library includes a number of functions that can perform hashing on data by applying different hashing algorithms such as md5, SHA2, HMAC etc. The encrypted value obtained is called as the hash of the original key. Processing…

PHP’s two data types – resource and NULL – are classified as special types. An object of resource type refers to external resources like database connection, file streams etc. On the other hand, a NULL data type is a variable without any data assigned to it. In this chapter, we shall learn more about these types. Resource Type A PHP…