ZEND PHP 5 Certification STUDY GUIDE

PHP Basics ” 31
Breaking and Continuing
The break keyword, which we encountered briefly in the earlier section about the
switch statement, can also be used to immediately exit a loop; it takes an optional
parameter, which allows you to exit from multiple nested loops:
i
$i = 0;
while (true) {
if ($i == 10) {
break;
}
echo $i . PHP_EOL;
$i++;
}
for ($i = 0; $i < 10; $i++) {
for ($j = 0; $j < 3; $j++) {
if (($j + $i) % 5 == 0) {
break 2; // Exit from this loop and the next one.
}
}
}
Remember to always terminate a break statement with a semicolon if it does not have
any parameters. If you do not do so and it is followed by an expression that returns an
integer number, you may end up causing the interpreter to randomly exit from more
than one loop—causing all sorts of difficult-to-troubleshoot situations.
There are cases in which, rather than terminating a loop, you simply want to skip
over the remainder of an iteration and immediately skip over to the next. This is
done with the continue statement—like with break, you can provide it an integer
parameter to specify the level of nesting to which the it applies. For example, the
following code will only output numbers between 0 and 3, and between 6 and 9:
Licensed to 482634 - Amber Barrow (itsadmin@deakin.edu.au)
for ($i = 0; $i < 10; $i++) {
if ($i > 3 && $i < 6) {
continue;
}