What is a RESTful service?
Representational State Transfer (REST) is an architectural style that specifies constraints, such as the uniform interface, that if applied to a web service induce desirable properties, such as performance, scalability, and modifiability, that enable services to work best on the Web.
What is PHP session_start() and session_destroy() function?
PHP session is used to store and pass information from one page to another temporarily (until user close the website). PHP session technique is widely used in shopping websites where we need to store and pass cart information e.g. username, product code, product name, product price etc from one page to another. PHP session creates unique user id for each browser to recognize the user and avoid conflict between multiple browsers.
What is a NULL pointer?
A special type of pointer that is does not point to anywhere, its points to no value. Usually used in places where we have nothing to pointer with nothing to point to. A pointer initialized as NULL is also a NULL pointer. Declaration Syntax: int *ptr = NULL; char *ptr = ‘\0’; float *ptr = (float *)0;