If you don't need it, don't use it ^^
Anyway you could use it for repetition in your code.
Completely idiot, but :
my_sum( parameter: a, parameter: b ) {
Return.Value: a + b
}
In you code, you use Function.my_sum(12, 23), which return 25.
You can use when you compare, like
SpriteX < Function.my_sum(Boss.X, Friend.X)…
Easier view ?
A good use, is for reset your game for example : at startup, you Reset(); when you clic Cancel, you Reset(); when you test after a key pressed, you can call Reset(); again…