Answer:
A function is defined before it is first invoked.
Explanation:
A function prototype is a term in computer programming that is used as the declaration of a function that specifies function's name, parameters and return type. However, unlike function itself, which specifies what it does, a function prototype specifies function's interface only and not what it does.
Hence, A function prototype can always be omitted when: a function is defined before it is first invoked.
