break and continue

break and continue

break, continue and Loop Idioms

break leaves a loop or switch at once; continue skips to the next pass. Both take a level count: break 2 leaves two nested loops, which replaces a "found" flag tested at every level.

break 2 to stop a nested search, continue 2 to skip a groupPHP

<?php
$shelves = ['A' => ['Dune', 'Emma', 'Ulysses'], 'B' => ['Beloved', 'Neuromancer'],
    'C' => ['Neuromancer', 'Walden']];
foreach ($shelves as $shelf => $titles) {     // find the first copy, then stop
    foreach ($titles as $pos => $title) {
        if ($title === 'Neuromancer') { echo "found at $shelf$pos\n"; break 2; }
    }
}
foreach ($shelves as $shelf => $titles) {
    foreach ($titles as $title) {
        if ($title === 'Beloved') continue 2; // abandon shelf B entirely
        if (strlen($title) < 5) continue;     // skip this title only
        echo "$shelf:$title ";
    }
}
echo "\n";

Output

found at B1
A:Ulysses C:Neuromancer C:Walden

A switch counts as a loop level, so a bare continue in a switch inside a loop only leaves the switch, and PHP warns: "continue" targeting switch is equivalent to "break". Did you mean to use "continue 2"? Other idioms: while (true) with one clear break for read-until-sentinel loops, count() hoisted out of a for condition, and array_find() or array_any() (array_find and Friends) for plain searches.

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