![]() 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. Note: Same results (with `$n = 10000000`) for PHP v7.4.33 using onlinephp(dot)io sandbox tool.PHP makes it relatively easy to build a web-based system, which is much of the reason for its popularity. Repeatedly show `empty` > `count` > `= `, but the margin is small and not worth the micro-optimizations. So things are not as clear as we might hope.ĥ => array(array(array(array(array())))),Ħ => array(array(), array(), array(), array(), array()),ħ => array(array(array(), array()), array(array(array(array(array(array(), array())))))),ġ2 => array(array(),array( "not empty" ),array(array()))Įcho " $key is_multiArrayEmpty= ". I confirm those results, and if you extend the test with isset($x->a->b->c) it appears that _isset is only called for the last property in the chain. See the earlier post by php at lanar dot com. (Some earlier posts wrongly suggest PHP just returns the negation of _isset). You need both functions.įor empty($m圜lass->foo), I believe PHP calls _isset, and if that is true returns the result of empty on the result of _get. ![]() Public function _construct ( $apple, $orange ) (experienced in PHP 5.6.3) The `empty()` can't evaluate `_get()` results explicitly, so the `empty()` statement bellow always renders true It actually seems that empty() is returning negation of the _isset() magic function result, hence the negation of the empty() result in the _isset() function above. Var_dump (empty( $registry -> notEmpty )) // false, finally! Return ( false = empty( $this -> _items )) In order to achieve desired (expexted?) results, you need to add _isset() magic function to your class: Although it's noted in the documentation above, I think it's worth mentioning in more detail as the behaviour is not straightforward. This is due to the fact that the empty() function uses _isset() magic functin in these cases. The result for empty($registry->notEmpty) is a bit unexpeced as the value is obviously set and non-empty. Var_dump (empty( $tmp )) // false as expected Var_dump (empty( $registry -> notEmpty )) // true. Var_dump (empty( $registry -> empty )) // true, so far so good Var_dump (empty( $registry -> notExisting )) // true, so far so good Please note that results of empty() when called on non-existing / non-public variables of a class are a bit confusing if using magic method _get (as previously mentioned by nahpeps at gmx dot de). Getting Started Introduction A simple tutorial Language Reference Basic syntax Types Variables Constants Expressions Operators Control Structures Functions Classes and Objects Namespaces Enumerations Errors Exceptions Fibers Generators Attributes References Explained Predefined Variables Predefined Exceptions Predefined Interfaces and Classes Predefined Attributes Context options and parameters Supported Protocols and Wrappers Security Introduction General considerations Installed as CGI binary Installed as an Apache module Session Security Filesystem Security Database Security Error Reporting User Submitted Data Hiding PHP Keeping Current Features HTTP authentication with PHP Cookies Sessions Dealing with XForms Handling file uploads Using remote files Connection handling Persistent Database Connections Command line usage Garbage Collection DTrace Dynamic Tracing Function Reference Affecting PHP's Behaviour Audio Formats Manipulation Authentication Services Command Line Specific Extensions Compression and Archive Extensions Cryptography Extensions Database Extensions Date and Time Related Extensions File System Related Extensions Human Language and Character Encoding Support Image Processing and Generation Mail Related Extensions Mathematical Extensions Non-Text MIME Output Process Control Extensions Other Basic Extensions Other Services Search Engine Extensions Server Specific Extensions Session Extensions Text Processing Variable and Type Related Extensions Web Services Windows Only Extensions XML Manipulation GUI Extensions Keyboard Shortcuts ? This help j Next menu item k Previous menu item g p Previous man page g n Next man page G Scroll to bottom g g Scroll to top g h Goto homepage g s Goto search
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