How to efficiently use try...catch blocks in PHP
Important note
The following discussion assumes that we are talking about code structured as in the example above: no matter which alternative is chosen, an exception will cause the method to logically stop doing whatever it was in the middle of.
As long as you intend to do the same thing no matter which statement in the try
block throws an exception, then it's certainly better to use a single try
/catch
. For example:
function createCar(){ try { install_engine(); install_brakes(); } catch (Exception $e) { die("I could not create a car"); }}
Multiple try
/catch
blocks are useful if you can and intend to handle the failure in a manner specific to what exactly caused it.
function makeCocktail(){ try { pour_ingredients(); stir(); } catch (Exception $e) { die("I could not make you a cocktail"); } try { put_decorative_umbrella(); } catch (Exception $e) { echo "We 're out of umbrellas, but the drink itself is fine" }}
For posterity sake,the answer maybe too late.You should check for the return value of the variable and throw an exception. In that case you are assured that the program will jump from where the exception is being raised to the catch block. Find below.
try{ $tableAresults = $dbHandler->doSomethingWithTableA(); if (!tableAresults) throw new Exception('Problem with tableAresults'); $tableBresults = $dbHandler->doSomethingElseWithTableB(); if (!tableBresults) throw new Exception('Problem with tableBresults');} catch (Exception $e) { echo $e->getMessage();}
It's more readable a single try catch block. If its important identify a kind of error I recommend customize your Exceptions.
try { $tableAresults = $dbHandler->doSomethingWithTableA(); $tableBresults = $dbHandler->doSomethingElseWithTableB();} catch (TableAException $e){ throw $e;} catch (Exception $e) { throw $e;}