Why choosing for (;;){} over while(1)?

Question

Possible Duplicate:
Is “for(;;)” faster than “while (TRUE)”? If not, why do people use it?

I see this

for (;;)
{
  // Some code here
}

quite often. But what benefits does it offer and why just not choose while(1){}?

Okay. I searched for it. But neither google nor Stackoverflow search function returned an adequate result. — ManuelSchneid3r, Nov 24 '12 at 20:28

score 5 · Accepted Answer · answered Nov 24 '12 at 20:27

5

They produce identical code. There are a couple of reasons why you might prefer for (;;) but it is all just personal preference:

Some compilers will warn you about conditions that are always true. for(;;) will not have that problem.
for (;;) literally reads as "Just loop forever!", whereas while (true) still appears to have some kind of condition.

I say pick one and stick with it. It doesn't matter as long as you don't switch between them arbitrarily.

answered Nov 24 '12 at 20:27

Joseph Mansfield

1

Personal opinion, but `for (;;)` literally reads as bad form to me, while `while(true)` literally reads as "Just loop forever!" They are completely identical in behavior and in assembly code produced by the compiler. – David Hammen Nov 24 '12 at 21:36
@DavidHammen Precisely! I was just giving a reason why `for (;;)` might be more common. – Joseph Mansfield Nov 24 '12 at 21:40

Sergey Kalinichenko · Answer 2 · 2012-11-24T20:31:16.960

4

This is the form of the forever loop that Kernighan and Ritchie used in their book^*. There is absolutely no other reason to prefer one form over the other.

^* Section 3.5 on While and For loops, example number four.

edited Nov 24 '12 at 20:31

answered Nov 24 '12 at 20:25

It's 1 character smaller. And [Go](http://golang.org/doc/effective_go.html#for) doesn't even have a while loop, so it's easier for Go programmers to understand? – beatgammit Nov 24 '12 at 20:29

score 3 · Answer 3 · answered Nov 24 '12 at 20:24

3

The two are equivalent and will most likely result in identical machine code. Choosing one over the other is a matter of personal preference.

answered Nov 24 '12 at 20:24

NPE

Not quite correct. They are (arguably) identical in effect, but not quite in the expressed meaning: One contains a "condition", the other doesn't. – stakx - no longer contributing Nov 24 '12 at 20:40
@stakx: They both contain conditions: one is always true, and the other is, well, always true. – NPE Nov 24 '12 at 20:43

score 2 · Answer 4 · answered Nov 24 '12 at 20:25

2

It does not really matter - it is just personal preference.

I like for(;;) better because I think it underlines loop forever aspect.

answered Nov 24 '12 at 20:25

mvp

And I think `while(true)` looks like a condition that will be `true` forever. :-) – Bo Persson Nov 24 '12 at 22:09

4 Answers4