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From: peters@cubsvax.UUCP (Peter S. Shenkin)
Newsgroups: net.lang.c
Subject: Re: condition convention 'if (10 == j)...'
Message-ID: <332@cubsvax.UUCP>
Date: Mon, 29-Apr-85 00:47:00 EDT
Article-I.D.: cubsvax.332
Posted: Mon Apr 29 00:47:00 1985
Date-Received: Tue, 30-Apr-85 02:30:43 EDT
References: <brl-tgr.9509> <137@bocklin.UUCP> <>
Reply-To: peters@cubsvax.UUCP (Peter S. Shenkin)
Organization: Columbia Univ Biology, New York City
Lines: 29
Summary: 


>> To prevent silly mistakes like 
>> 	if (j = 10)
>> I usually write
>> 	if (10 == j)
>> By putting the constant first, I ensure that the compiler will catch the 
>> typo.
>
>I think this is a good idea.  Any criticisms?  The only problem
>I have with it is that I am not accustomed to reading code written
>this way.
>-- 
>Gordon A. Moffett               ...!{ihnp4,cbosgd,sun}!amdahl!gam

Just that instead of writing, in the traditional manner,
	if(pc=malloc(nbytes)==NULL)...
you have to insert extra parens if you use the other form:
	if(NULL==(pc=malloc(nbytes)))..
This is because == has higher precedence than =, and the expression will
first evaluate NULL==pc, then try to set the resulting constant to whatever 
malloc() returns (except, of course, the compiler doesn't let you get that far).

I used to use the (NULL==var form but reverted to the more traditional
form because the extra parens kept making me do a double-take.
I'd rather skip the parens and always put the constant at the end. That way
I always know where to look for it.  You pays your money & takes your choice.
If it weren't for this problem, though, I'd use the proposed form.

Peter S. Shenkin,  Biology, Columbia Univ.   cubsvax!peters