![]() ![]() ![]() If you have to put up with them coming in from outside, check for them as above and move on.īut isset($plainvariable)? You need to step back a bit and ask yourself why. Often, though, passing nulls around a lot is a bit of a code smell (it's short for "I really don't know what value to put in this variable, I shouldn't even be using it to be honest with myself"). Oh, maybe you want to see if the variable contains an actual null-type null? You should say so for the sake of self-documenting code: $plainvariable = null or is_null($plainvariable). isset($object->field) if there's duck-typing going on. Isset($compositevariable), sure: if you get passed an array, PHP doesn't give you any guarantee it has all the fields you might want to look at (and note that array_key_exists is more strict about what counts as "set"). Really, how much of a use case is there for isset($plainvariable)? Is your function so wildly out of control that you can't keep track of whether your variables have even been initialized or not? That would be the real problem. In a nutshell, you should think twice, whether you want to use such operators, or you want to have your variables more organized and take PHP to warn you about possible issuesĪ bit of a digression, because it has nothing to do with empty(), but. See an excellent comment from Hayley Watson and also an article I wrote about such a misuse. Same goes for the expressions as well.Īn important note: as a matter of fact, both isset() and empty(), as well as a null coalescing operator often get misused. It would be overkill again, because for the already declared variable, if(!empty($var)) would be exactly the same as just if($var) which is way more clean and readable. On the other hand, people often use empty() against a variable that deliberately exists. So now you can tell that checking for both isset() and empty() is an obvious overkill and empty() alone is more than enough, making the initial condition as simple as if (!empty( $someVar )) ![]() this code being the exact definition for !empty(), because the very purpose of this function is to tell whether a variable is either not set or "empty". This function returns true if the variable exists. So you can tell that the above snippet could be shortened to if (isset( $someVar ) & $someVar )īut the most funny part is. The isset() function checks whether a variable is set, which means that it has to be declared and is not NULL. The below code can be seen too often to be ignored on this site dedicated to treating PHP delusions, being one of the most frequent cases: if (isset( $someVar ) & !empty( $someVar ))īeing unfamiliar with PHP's loose typing, learners often mistake if(!empty($someVar) with just if($someVar), thinking empty() will check for the empty-like values such as an empty string, a zero and such, whereas in PHP, for this purpose could be used the variable itself: thanks to the type juggling, when used in the conditional operator, any value will be cast to boolean, which will effectively check for the "emptiness" already, making a dedicated function quite useless. This will return true if the value is set to. Empty is interpreted as: "" (an empty string), 0 (integer), 0.0 (float)`, "0" (string), NULL, FALSE, array() (an empty array), and "$var " (a variable declared, but without a value in a class.Do you really need to check for both isset() and empty() at the same time? isset This will check to see if there is a value for an item in an array. This will produce the following output − 0 is set with isset functionĮMPTY checks to see if a variable is empty. That means variables assigned a "", 0, "0", or FALSE are set, and therefore are TRUE for ISSET. ISSET returns TRUE if the variable exists and has a value other than NULL. In other words, it checks to see if the variable is any value except NULL or not assigned a value. ISSET checks the variable to see if it has been set.
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