PHP finally Block: Code That Always Runs

A finally block runs no matter what happens in the try: success, an exception, or even a return. It is the right place for cleanup.

index.php

PHP

<?php
function work(bool $fail): void
{
    try {
        echo "Start\n";

        if ($fail) {
            throw new RuntimeException("boom");
        }

        echo "Done\n";
    } catch (RuntimeException $e) {
        echo "Caught: " . $e->getMessage() . "\n";
    } finally {
        echo "Cleanup\n";
    }
}

work(false);
echo "---\n";
work(true);

Output

OUTPUT

Start
Done
Cleanup
---
Start
Caught: boom
Cleanup

Cleanup is printed in both cases.

A typical use: close what you opened

index.php

PHP

<?php
$handle = fopen("data.txt", "w");

try {
    fwrite($handle, "important data");
    throw new RuntimeException("something went wrong while writing");
} catch (RuntimeException $e) {
    echo "Error: " . $e->getMessage() . "\n";
} finally {
    fclose($handle);
    echo "File closed";
}

Output

OUTPUT

1
2

Error: something went wrong while writing
File closed

Without finally, an exception could skip fclose() and leave the file open.

try and finally without catch

You can use finally alone. The exception still travels upward, but the cleanup runs first.

index.php

PHP

<?php
function risky(): void
{
    try {
        throw new LogicException("not handled here");
    } finally {
        echo "Cleaning up\n";
    }
}

try {
    risky();
} catch (LogicException $e) {
    echo "Caught outside: " . $e->getMessage();
}

Output

OUTPUT

1
2

Cleaning up
Caught outside: not handled here

finally and return

finally runs even when the try has already hit return.

index.php

PHP

<?php
function test(): string
{
    try {
        return "from try";
    } finally {
        echo "finally runs first\n";
    }
}

echo test();

Output

OUTPUT

1
2

finally runs first
from try

dangerous

A return inside finally wins

If finally itself contains return, it replaces the earlier return and swallows exceptions. Avoid return and throw inside finally unless you are sure.

Common uses

Close files, database connections or locks.
Release a lock (flock($h, LOCK_UN)).
Roll back a database transaction when something fails.
Remove temporary files.

index.php

PHP

<?php
$lock = fopen("job.lock", "c");
flock($lock, LOCK_EX);

try {
    echo "Doing exclusive work\n";
} finally {
    flock($lock, LOCK_UN);
    fclose($lock);
}

Output

OUTPUT

Doing exclusive work

lightbulb

Not every cleanup needs finally

PHP frees memory and closes files at the end of the script. Use finally when cleanup matters before the script ends, such as locks and transactions.