PHP switch Statement: Cases, break and Fallthrough

switch ($value) compares one value against a list of case labels and runs the code under the first label that matches. Each case ends with break; default handles everything that matched nothing.

<?php
$day = 'sat';

switch ($day) {
    case 'mon':
        echo "Start of the week";
        break;
    case 'fri':
        echo "Almost weekend";
        break;
    case 'sat':
    case 'sun':
        echo "Weekend";
        break;
    default:
        echo "A regular weekday";
}

Set $day to 'fri', 'sun' or 'wed' and run it again. The default case does not need a break when it is the last one.

Multiple cases for one block

To run the same code for several values, stack the case labels with nothing between them. A matching label continues into the code below it.

<?php
$extension = 'jpeg';

switch ($extension) {
    case 'jpg':
    case 'jpeg':
    case 'png':
    case 'webp':
        $type = 'image';
        break;
    case 'mp4':
    case 'mov':
        $type = 'video';
        break;
    default:
        $type = 'unknown';
}

echo "Type of .$extension: $type";

Unlike match, a switch has no case 'jpg', 'jpeg': comma syntax. Stacked labels are the only way.

Fallthrough: what happens without break

break is what stops a switch. Without it, PHP runs the matching case and then keeps going into every case below, ignoring their labels, until it hits a break or the end.

<?php
$plan = 'pro';

echo "Features for $plan:\n";
switch ($plan) {
    case 'enterprise':
        echo "- single sign-on\n";
    case 'pro':
        echo "- unlimited projects\n";
    case 'free':
        echo "- 3 projects\n";
        echo "- community support\n";
}

Here the fallthrough is on purpose: each plan gets its own features plus everything from the cheaper plans. When you write it deliberately, add a comment such as // no break so the next reader does not "fix" it. When you did not mean it, a missing break is one of the most common switch bugs.

switch uses loose comparison (==)

Every case is checked with ==, not ===. A numeric string matches a number, null matches false and "", and true matches any value that counts as true. Tap the cells to compare the two operators.

The practical consequence: an input string "1" from a form lands in case 1: without any conversion, which is often what you want. But switch (true) with a non-empty string, or null meeting case false:, can pick a case you did not expect.

<?php
function describe(mixed $value): string
{
    switch ($value) {
        case 0:
            return "zero";
        case "10":
            return "ten";
        case false:
            return "false-ish";
        default:
            return "something else";
    }
}

echo describe("0"), "\n";    // "0" == 0
echo describe(10), "\n";     // 10 == "10"
echo describe("1e1"), "\n";  // "1e1" == "10" (both are numeric)
echo describe(null), "\n";   // null == 0
echo describe(""), "\n";     // "" == false
echo describe("a"), "\n";

Note the null line: it never reaches case false:, because null == 0 is already true and case 0: comes first. With loose comparison, the order of the cases changes the result. Since PHP 8, 0 == "a" is false (in PHP 7 it was true), so a non-numeric string no longer matches case 0:. If you need ===, use a match expression, covered at the end of this page.

switch(true) for ranges and conditions

A case label can be any expression. With switch (true), each case is a condition, and the first one that equals true wins.

<?php
$score = 83;

switch (true) {
    case $score >= 90:
        $grade = 'A';
        break;
    case $score >= 80:
        $grade = 'B';
        break;
    case $score >= 70:
        $grade = 'C';
        break;
    default:
        $grade = 'F';
}

echo "Score $score is grade $grade";

Make sure every case is a real boolean. Because of loose comparison, case $name: would match whenever $name is a non-empty string.

switch inside a loop: break and continue

Inside a loop, break in a switch only leaves the switch, not the loop. To stop the loop, use break 2. continue inside a switch behaves like break, and PHP warns at compile time: "continue" targeting switch is equivalent to "break". Did you mean to use "continue 2"?. Write continue 2 to skip to the next loop iteration.

<?php
$commands = ['add', 'skip', 'add', 'stop', 'add'];
$total = 0;

foreach ($commands as $command) {
    switch ($command) {
        case 'add':
            $total++;
            break;        // leaves the switch only
        case 'skip':
            continue 2;   // next foreach iteration
        case 'stop':
            break 2;      // leaves the foreach
    }
    echo "after $command, total = $total\n";
}

echo "Final total: $total\n";

switch vs match

PHP 8 added match, which covers most uses of switch with less code. It compares with ===, returns a value, never falls through, allows comma separated conditions, and throws an UnhandledMatchError when nothing matches, so a forgotten case cannot pass silently.

<?php
$status = 404;

// switch
switch ($status) {
    case 200:
    case 201:
        $text = 'OK';
        break;
    case 404:
        $text = 'Not found';
        break;
    default:
        $text = 'Error';
}
echo $text, "\n";

// match
echo match ($status) {
    200, 201 => 'OK',
    404 => 'Not found',
    default => 'Error',
}, "\n";

Keep switch when a case needs several statements, or when fallthrough is the point, as in the plan example. For mapping a value to a result, match is shorter and safer.