Advanced UFT 12 for Test Engineers Cookbook

Implementing function pointers

What is a function pointer? A function pointer is a variable that stores the memory address of a block of code that is programmed to fulfill a specific function. Function pointers are useful to avoid complex switch case structures. Instead, they support direct access in runtime to previously loaded functions or class methods. This enables the construction of callback functions. A callback is, in essence, an executable code that is passed as an argument to a function. This enables more generic coding, by having lower-level modules calling higher-level functions or subroutines.

This recipe will describe how to implement function pointers in VBScript, a scripting language that does not natively support the usage of pointers. ...