What does: "while( (stuff) ? false : (otherstuff)){}" mean?

Question

I have a c++ while loop I'm looking at:

while ((stuff) ? false : (otherstuff))
{
  commands;
}

And I don't really understand what it's trying to do with the "? false :" part? Can any one explain what this means please? I already tried looking it up but I'm not really getting anything helpful.

Do you know what `?:` operator is? – AnT May 04 '16 at 00:59 — AnT, May 04 '16 at 00:59
It's a convoluted way to say `while(!stuff && otherstuff)` – Matteo Italia May 04 '16 at 01:04 — Matteo Italia, May 04 '16 at 01:04
no, I don't. I've never used it before. – purpleminion May 04 '16 at 01:06 — purpleminion, May 04 '16 at 01:06

score 2 · Answer 1 · answered May 04 '16 at 01:04

2

It's using the ternary conditional operator to effectively perform the check:

while (!(stuff) && (otherstuff))

If stuff is true, then the first option on the ternary is evaluated (evaluating to false), if it's false, then it evaluates to otherstuff.

answered May 04 '16 at 01:04

ShadowRanger

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score 0 · Answer 2 · answered May 04 '16 at 01:04

0

It's just a really bad way of writing this:

while (!stuff && otherstuff) {

}

answered May 04 '16 at 01:04

Dietrich Epp

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What does: "while( (stuff) ? false : (otherstuff)){}" mean?

2 Answers2