How to know the function of a method just by looking at the return type of that method

Question

my teacher know what will the predefine function will do just by looking at the return type

Answer 1

its not possible unless its as simple as return i*j;

or juat seeing i*j and saying yep thats going to return an interger.

Answer 2

@thomas yes thats right he could say what will be returned but he wouldent know what the function is doing just by looking at the functions return.

Answer 3

Wow! I also want to know that... Great question.

Answer 4

His teaching us android studio.
He will know what method wikl be called according to return type either void int string or bool