The cert guide is maybe not 100% clear on the question of breaking out of a loop, but you can break and continue in all types of loops - for, while and foreach (the latter wasn't mentioned in the loops section of the book).
About the continue when in nested loops. Well, it is true that you can do
< ?php
for ($i = 0; $i < 10; $i++){
for ($j = 0; $j < 10; $j++){
if ($i % 2) {
continue 2;
}
}
// this line will be executed 5 times
// and will write 0 2 4 6 8
echo $i;
}
?>
Or you can just continue or continue 1, rather than continue 2, like this
< ?php
for ($i = 0; $i < 10; $i++){
for ($j = 0; $j < 10; $j++){
if ($i % 2) {
continue;
}
}
// this line will be executed 10 times
// and will write 0 1 2 3 4 5 6 7 8 9
echo $i;
}
?>
So yes, it is possible, but to me, these continue 2, continue 3 and so on can only cause confusion and make the code harder to follow. If I find myself in situation where I write continue 2, I would seriously think about restructuring this particular piece of logic.
