Functions
This is using the Built-In Function
This is the original text: hello, operator
This is the new one using strtoupper() : HELLO, OPERATOR
User Defined Function
4.99 beef jerky
1.99 soda
7.329
3.49 large bag of chips
5.99 ham and cheese sandwich
9.954
Functions are useful in many situations. Developers can program more complex tasks and can reuse those functions for more efficiency and time.
However, developers shouldn't name their function the same as built-in functions. This will lead to a lot of problems.