Having the prototype available before the first use of the function allows the compiler to check that the correct number and type of arguments are used in the function call and that the returned value, if any, is being used reasonably. The function definition itself can act as an implicit function declaration.
While shellac is not usually the finish paint choice, it is often thought of as the best paint primer available. It has properties that oil and water based paints can't match, and provides a more dependable seal than most other primers are able to provide.
do this step outside if using the spray shellac since the shellac has a serious strong odor but the smell goes away quick and dries in minutes and just to reiterate this when you have a piece of furniture made out of different types of wood keep in mind that when you paint the color can appear differently