Functions - How do they return

[victorf]

[dkinzer]

What you suggest will work and is commonly done. In your function, "foo" is an automatically-defined local variable that has the same type as the function. This is called the "return value variable" and it always has the same name as the function itself. You can use it just like any other variable meaning that you can assign to it, pass it (by value or by reference) to another procedure, take its address, etc.

As a side note, the name of the function has two different meanings within the function itself. When used one way, it refers to the return value and when used in another way, it refers to the function itself. Consider the following code:

[victorf]

[mikep]

It is recursion. Don was making 2 points:
1. Explicit: how the compiler differentiates between the return value foo and the call to the function foo
2. Implicit: The fact that the ZBasic language supports true recursion whereas BasicX cannot support this syntax and you need two functions that mutually call each other for the same effect.

[dkinzer]

[victorf]

[mikep]

Recursion depth depends on the amount of stack taken up by the parameters, the return result and the intermediate calculations of your recursive function. Section 3.18 (http://www.zbasic.net/doc/ZBasicRef/ZBasicRef69.html) discusses function recursion and section 3.11 (http://www.zbasic.net/doc/ZBasicRef/ZBasicRef64.html) discusses runtime stack checking.

Here is an example program that uses a recursive function to calculate the simple series 1 + 2 + 3 ... From high school math we know the sum is

[dkinzer]