Category: Advanced

The acronym CSPRNG stands for Cryptographically Secure Pseudorandom Number Generator. PHP function library includes many functions that generate random numbers. For example − Example The following code shows how you can use the function mt_rand() to generate random numbers − <?php # Generates random integer between the range echo “Random integer: ” . rand(1,100) . PHP_EOL; #…

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 doesnt 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. header(string$header,bool$replace=true,int$response_code=0):void The string parameter is passed to the header() function. For example header(“HTTP/1.1 404 Not Found”); It is…

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…

The PHP Variable Handling is_null() function is used to checks whether a variable is null. It returns true when the variable is null. It returns false if the variable contains any value. This function is useful for determining if a variable is empty. It helps prevent errors caused by missing values. It can run PHP 4, PHP…

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…