Inline functions:

a function is stored only once in the computer memory. No matter how many function calls you have in your program. This saves computer memory.	computer has to spend extra time and memory to switch to the function and back to the program. It may not be convenient to write functions for very simple tasks!
Inline functions (only exist in C++) are repeated everytime you issue a function call.	spend memory by repeating code; saves time and instructions to switch back and forth;

How do we?

precede the header with the keyword: inline

illustration