PHP try-catch block inside loop [duplicate]

Answer 1

There is most likely no difference. Optimization on this level does usually not make any sense in an interpreted language like PHP.

In most cases, your logic will require you to put the block inside the loop anyway. Otherwise, the loop will continue even if an error has occurred.

Answer 2

That entirely depends on the nature of the failure, and what you intend to do in the catch.

But I'd generalize it like so

• If you want the loop to exit on Exception, wrap the whole loop
• If you want the loop to continue, don't

EDIT

Exceptions caught inside a loop don't implicitly break the loop

for ($i = 1; $i < 10; $i++) {
    try {
        if ($i % 3 == 0) {
            throw new Exception('BOOM');
        }
        echo $i;
    } catch (Exception $e) {
        echo "Exception at $i";
    }
    echo PHP_EOL;
}

output:

1
2
Exception at 3
4
5
Exception at 6
7
8
Exception at 9

Whereas those caught outside the loop do

try {
    for ($i = 1; $i < 10; $i++) {
        if ($i % 3 == 0) {
            throw new Exception('BOOM');
        }
        echo $i, PHP_EOL;
    }
} catch ( Exception $e ) {
    echo "Exception at $i";
}

output:

1
2
Exception at 3

Answer 3

Of course, there's a difference, in the most obvious way int the first case you will only check for errors before entering the loop, if the loop doesn't have exception throwers, leave it that way. In the other hand you will be checking it in each iteration, wich you'll need if you have sentences or methods ... wich can have exceptions.

I'dont know if i explain myself well, let me know if you understand

Answer 4

That depends entirely on how you are using the try-catch? Is it safe to continue looping through your subject if an exception was thrown?