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From: Phil Carmody <pc+usenet@asdf.org>
Newsgroups: comp.lang.c
Subject: Re: while(T[l]<p & l<=r)
Date: Sun, 14 Apr 2024 23:32:23 +0300
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Janis Papanagnou <janis_papanagnou+ng@hotmail.com> writes:
> On 27.03.2024 12:35, fir wrote:
>> tell me, is while(T[l]<p & l<=r) the same as while((T[l]<p)&&(l<=r))
>
> 1. As long as K&R precedences still hold you don't need the inner
> parentheses; '<' and '<=' has higher precedence than '&' and '&&'.
> 2. In this case where you compare predicate expressions that
> evaluate to '0' and '1' on both sides of '&' and '&&' respectively
> these expressions are (while not the same) equivalent _here_.

The latter has shortcut semantics, and will only evaluate
r, and l a second time, if the first expression is true.
If r or l are memory mapped I/O, or similar, you might be
changing externally visible behaviour.

Phil
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