Break levels in PHP

I have this snippet of code and it's working just fine (because in my example that variable really exists in $arrival_time so it breaks at about $k = 10).

$arrival_time = explode(",", $arrival_timeAll[1]);

$sizeOfArrival = sizeof($arrival_time);
$k = -1;
while (++$k < $sizeOfArrival) {
    if ($arrival_time[$k] >= $someVariable) {
            break;
    }
}

Isn't that the same as this code? I added the while(true) loop and increased the "break level" - so it's now break 2, not just break. But seems that's an infinite loop. Why?

while (true) {
    $arrival_time = explode(",", $arrival_timeAll[1]);

    $sizeOfArrival = sizeof($arrival_time);
    $k = -1;
    while (++$k < $sizeOfArrival) {
        if ($arrival_time[$k] >= $someVariable) {
            break 2;
        }
    }
}

Why adding while(true)? Because I need to define some more statements (which here aren't neccesary for expla开发者_Go百科nation) if inside while loop doesn't find the matching one (if that "break" in first case, "break 2" in second case doesn't run).

Anyway - why this isn't working?

In some cases, the predicate for the inner while loop is never hit, thus the while loop is never executed. As you don't have a break after it, the loop will run forever. This case would be if the array is empty, 0 < 0 is false.

Starting with $k = -1, the first time the predicate gets evaluated, $k will be 0 as you are using the preincrement operator, for an empty array this will evaluate to false and the code with run infinite. Without the while(true) loop this wouldn't cause any problems as you'd just jump straight over it.