What does a while loop that ends with a semicolon mean?

Question

I came across this piece of code but I'm not familiar with this while loop syntax.

while(i < j){
    while(distance(arr[++i]) < distance(p));
    while(distance(arr[--j]) > distance(p));
    if(i < j){
        swap(arr, i, j);
    }
}

I've never seen a while loop without braces that end in semicolons. What do they mean?

Nothing other than no body is present as none is needed. The functionality is all in the loop condition. A terminating semicolon is often a mistake by beginners (then they wonder why the body doesn't execute) but not in this case — g00se, Aug 03 '23 at 09:49
you could, instead of a semicolon, use empty braces (`while (condition) { }`), same result — user16320675, Aug 03 '23 at 10:02
Duplicate of [Semicolon at end of 'if' statement](https://stackoverflow.com/questions/14112515/semicolon-at-end-of-if-statement) — Mark Rotteveel, Aug 03 '23 at 12:21
if you want to Google it, search for "Java empty statement". It is also known as a "null statement". — Old Dog Programmer, Aug 03 '23 at 13:15

score -1 · Answer 1 · edited Aug 03 '23 at 12:18

-1

while(cond);

is the same as

while(cond) {}

edited Aug 03 '23 at 12:18

Mark Rotteveel

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answered Aug 03 '23 at 09:49

Chr L

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I have removed your final comment. It works because a while is followed by a statement or a block, and just `;` is considered a valid statement in Java (and empty statement). – Mark Rotteveel Aug 03 '23 at 12:19
Regardless that your answer is correct or not, you are encouraged to edit it to explain why this is the best answer to the question. – Tom Solid Aug 04 '23 at 11:43

What does a while loop that ends with a semicolon mean?

1 Answers1