Forward declaration (was Re: Novice question.)

[loki]

In article <1990Nov14.143802.23021 at noose.ecn.purdue.edu>,
 longshot at monkey.ecn.purdue.edu (The Knight Guard) writes:
>>	"extern" means that the variable is global, and was declared in a
>>separate .c file.  If your program occupies only 1 file, you will never
>>use this.
>>
>>John Gordon
> 
> 	Not true here...  Our cc seems to require that all functions/procedures
>   be defined before the main block.  The way around this is to extern all 
>   functions before main...  Dunno if this is just our compiler, anyone else
>   seen this?  Any ideas of why?

I'm not sure what compiler/environment you're using, but you will often find
that a function used in main() is assumed to return type int unless the 
compiler has reason to believe otherwise.  When the function appears later
in the text and returns a different type, the compiler accuses you of
redefining it.

You should be able to work around this by defining the return type expected
within main(), e.g.

	main()
	{
		int a,b;
		double bogus();
		.
		.
		.
	}

The above just lets the compiler know about bogus()'s return type, and you
needn't specify the parameters to the function, just its type.

Hope this helps.

Max J.