As there are limited number of standard functions built-in on Qbasic, soon it will be not enough to meet the users requirements. So, Qbasic allows users to create some new functions that work like a library function.
- These functions created by user according to their need for easiness in the program are called user defined functions (UDF).
- A user defined function is written by computer programmer to do specific task. A User-Defined Function (UDF) is a function provided by the user of a program or environment, in a context where the usual assumption is that functions are built into the program or environment.