Knowing it could help us to improve our code in speed and readability.
So the above logic is flawed.We are all good programmers and we know how to write good programs, but there are some hidden things we might have missed in the programming world. But, as discussed, isset($data) will also return false if $data was set, but was set to null. The author of this code presumably wanted to check if keyShouldBeSet was set in $data. do something here if 'keyShouldBeSet' is not set This behavior is more problematic than it might appear at first and is a common source of problems.Ĭonsider the following: $data = fetchRecordFromStorage($storage, $identifier) Unset($value) // $value no longer references $arrĬommon Mistake #2: Misunderstanding isset() behaviorĭespite its name, isset() not only returns false if an item does not exist, but also returns false for null values. To still get the benefit of using references in foreach loops without running the risk of these kinds of problems, call unset() on the variable, immediately after the foreach loop, to remove the reference e.g.: $arr = array(1, 2, 3, 4)
Not sure how to use foreach loops in PHP? Using references in foreach loops can be useful if you want to operate on each element in the array that you are iterating over. Common Mistake #1: Leaving dangling array references after foreach loops This article highlights ten of the more common mistakes that PHP developers need to beware of.
But its ease of use notwithstanding, PHP has evolved into quite a sophisticated language with many frameworks, nuances, and subtleties that can bite developers, leading to hours of hair-pulling debugging. PHP makes it relatively easy to build a web-based system, which is much of the reason for its popularity.