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Path: utzoo!utgpu!jinli
From: jinli@gpu.utcs.toronto.edu (Jin Li)
Date: Fri, 24-Mar-89 13:41:56 EST
Message-ID: <1989Mar24.134156.11510@gpu.utcs.toronto.edu>
Organization: University of Toronto Computing Services
Newsgroups: comp.lang.c
Subject: Re: Problem returning doubles from a function
References: <39722@csvax1.cs.tcd.ie>
Reply-To: jinli@gpu.utcs.UUCP (Jin Li)

In article <39722@csvax1.cs.tcd.ie> omahony@csvax1.cs.tcd.ie (Donal O'Mahony - OMAHONY@cs.tcd.ie) writes:
>Can anone explain the problem with the following program (made up of 2 files).
>
>::main.c
>#include <stdio.h>
>main()
>{double a,b;
>
>  a = 1.234;
>  b = store_length(a);

You should explicitly declare the type for 'store_length'.
ie. you do 'extern double store_length();' at the beginning.
The reason is that C assumes undeclared functions having
'int' as their type.  Thus, value returned from 'store_length'
will be implicitly casted to 'int' before assigned to var 'b'.

>[deleted]...
>
>::rt1.c
>double store_length( double measurements)
>{  measurements= 2;

It is always a good idea to initialize 'double' var using
floating point representation. ie. 2.0 instead of 2

-- 
  		    Jin Li		      >>     Gin & Tonic mix well
   University of Toronto Computing Services  <<       No bugs, no bucks
jinli@gpu.utcs.utoronto.ca   uunet!utgpu!jinli>>         ls is a typo