How does a function differ from a procedure?

Answer 1

In closed subroutine a subroutine stored outside the main routine can be connected to it by linkages at one or more locations.

whereas in open subroutine is a set of computer instructions i.e. a subroutine that performs some particular program and insert them directly each and every time that particular function is required

Answer 2

Nothing. Functions and subroutines are the same thing, as are procedures. Although we often think of a function as being a procedure or subroutine that returns a value, not all functions return a value; some functions are purely functional.

Answer 3

A function is a section of code that takes no or more parameters and returns a result. Generally, a well behaved function has no side-effects. An example is sin(x). A subroutine is a section of code that takes no or more parameters and returns no result. It can also have side-effects, such as modifying the value of one of the parameters, assuming call-by-reference semantics. An example is fclose(file). Differences depend on the language, such as C/C++ vs FORTRAN. The "no side-effect" rule is not hard and fast. You can write functions or subroutines that make changes, such as to open a file, read it, close it, etc. Generally, concern about side-effects relate to optimization or to modular design. One big area of concern for the "non side-effect" rule is thread-safeness, where you need to know if the routine affects things on a global basis. It comes down to what you want to do, and how the language you are using supports that need.

Answer 4

Sub routines are used inside programs, sort of like a g70 or g71 as you state a start block and end block and the computer follows the path. A sub program is a secondary program called up by the main program that works well for repetitive tool paths.

Answer 5

A function returns a value whereas a subroutine does not. A function should not change the values of actual arguments whereas a subroutine could change them.

Answer 6

A function returns a value, a subroutine does not.

Answer 7

Usually a function is considered a type of procedure (which also includes things like subroutines and methods), though it seems like this definition isn't concrete.