Article View: comp.lang.modula2
Article #4599Re: "for" loops (was Re: C++ vs. Modula2)
From: Devin_E_Ben-Hur
Date: Sat, 28 Jan 1989 20:43
Date: Sat, 28 Jan 1989 20:43
43 lines
1619 bytes
1619 bytes
Jeff Boeing writes:
> Actually, C's "for" can be duplicated EXACTLY by C's "do ... while" loops.
> Consider:
>
> for (i = 0; i <= 17; ++i)
> {
> stuff();
> more_stuff();
> }
>
> versus:
>
> i = 0;
> do {
> stuff();
> more_stuff();
> } while (++i <= 17);
>
>
> These two iterations are indistinguishable from one another. The "for" term
> in C is totally superfluous and is only included because it makes it look
> languages that have a more "for"-ish "for" statement, like Pascal or Modula.
Nope. This is the actual equivalent code:
i = 0;
while (i <= 17) {
stuff();
more_stuff();
continue_here:
++i;
}
The for loop tests at the first iteration, and a continue statement will
branch to the increment not to the test.
The C for statement is a convenience allowing the programmer to place
all loop control statements in one place instead of spreading them all
over the loop. I've always thought the limits placed on Pascal & Modula's
for statements were silly, but that's just MHO.
Devin_Ben-Hur@cup.portal.com
...!ucbvax!sun!cup.portal.com!devin_e_ben-hur
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Path: arc1-ca.pugleaf.net!utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!amdahl!uunet!portal!cup.portal.com!Devin_E_Ben-Hur From: Devin_E_Ben-Hur@cup.portal.com Newsgroups: comp.lang.modula2,comp.lang.c Subject: Re: "for" loops (was Re: C++ vs. Modula2) Message-ID: <14049@cup.portal.com> Date: 28 Jan 89 20:43:57 GMT References: <INFO-M2%89011219330825@UCF1VM> <739@jupiter.iis.UUCP> <1611@csuna.UUCP> Organization: The Portal System (TM) Lines: 43