Is there something similar in PHP to the try ... else in Python?
I need to know if the try block executed correctly as when the block executed correctly, a message will be printed.
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6 Answers
PHP does not have try/catch/else. You could however set a variable in the catch block that can be used to determine if it was run:
$caught = false;
try {
// something
} catch (Exception $e) {
$caught = true;
}
if (!$caught) {
}
I think the "else" clause is a bit limiting, unless you don't care about any exceptions thrown there (or you want to bubble those exceptions)... From my understanding of Python, it's basically the equivalent of this:
try {
//...Do Some Stuff Here
try {
// Else block code here
} catch (Exception $e) {
$e->elseBlock = true;
throw $e;
}
} catch (Exception $e) {
if (isset($e->elseBlock) && $e->elseBlock) {
throw $e;
}
// catch block code here
}
So it's a bit more verbose (since you need to re-throw the exceptions), but it also bubbles up the stack the same as the else clause...
Edit Or, a bit cleaner version (5.3 only)
class ElseException extends Exception();
try {
//...Do Some Stuff Here
try {
// Else block code here
} catch (Exception $e) {
throw new ElseException('Else Clasuse Exception', 0, $e);
}
} catch (ElseException $e) {
throw $e->getPrevious();
} catch (Exception $e) {
// catch block code here
}
Edit 2
Re-reading your question, I think you may be overcomplicating things with an "else" block... If you're just printing (which isn't likely to throw an exception), you don't really need an else block:
try {
// Do Some stuff
print "Success";
} catch (Exception $e) {
//Handle error here
print "Error";
}
That code will only ever print either Success or Error... Never both (since if the print function throws the exception, it won't be actually printed... But I don't think the print CAN throw exceptions...).
Not familiar with python but it sounds like you're after Try Catch blocks used with exceptions...
Comments
There is try-catch in php.
Example:
function inverse($x) {
if (!$x) {
throw new Exception('Division by zero.');
}
else return 1/$x;
}
try {
echo inverse(5) . "\n";
echo inverse(0) . "\n";
} catch (Exception $e) {
echo 'Caught exception: ', $e->getMessage(), "\n";
}
// Continue execution
echo 'Hello World';
1 Comment
vokimon
The question was about php equivalent to python's "try-else", that is having a compact way of executing a block of code after the try block whenever no exception is thrown.
try {
$clean = false;
...
$clean = true;
} catch (...) { ... }
if (!$clean) {
//...
}
That's the best you can do.
You can use try { } catch () { } and throw. See http://php.net/manual/en/language.exceptions.php
try {
$a = 13/0; // should throw exception
} catch (Exception $e) {
echo 'Caught exception: ', $e->getMessage(), "\n";
}
or manually:
try {
throw new Exception("I don't want to be tried!");
} catch (Exception $e) {
echo 'Caught exception: ', $e->getMessage(), "\n";
}
7 Comments
ircmaxell
I didn't downvote, but he was asking about the
else block, not exceptions in general...ircmaxell
Oh, and
$a = 13/0; will not throw an exception unless you have an error handler installed that throws exceptions (set_error_handler(function($errno, $errstr, $errfile, $errline) { throw new ErrorException($errstr, 0, $errno, $errfile, $errline);});... php.net/manual/en/class.errorexception.php)
enobrev
Is PHP's "catch" block not equivalent to Python's "else" block?
webbiedave
@enobrev: No it isn't. See my answer below.
ircmaxell
@enobrev, the difference is that exceptions thrown in the
else clause are not caught by the except/catch block. So a little more logic is required than just placing the else within the try (as my answer tries to communicate)... |