Php/docs/arrayaccess.offsetexists
ArrayAccess::offsetExists
(PHP 5, PHP 7, PHP 8)
ArrayAccess::offsetExists — Whether an offset exists
Description
abstract public ArrayAccess::offsetExists
( mixed $offset
) : bool
Whether or not an offset exists.
This method is executed when using isset() or empty() on objects implementing ArrayAccess.
Note:
When using empty() ArrayAccess::offsetGet() will be called and checked if empty only if ArrayAccess::offsetExists() returns
TRUE.
Parameters
offset- An offset to check for.
Return Values
Returns TRUE on success or FALSE on failure.
Note:
The return value will be casted to bool if non-boolean was returned.
Examples
Example #1 ArrayAccess::offsetExists() example
<?phpclass obj implements arrayaccess { public function offsetSet($offset, $value) { var_dump(__METHOD__); } public function offsetExists($var) { var_dump(__METHOD__); if ($var == "foobar") { return true; } return false; } public function offsetUnset($var) { var_dump(__METHOD__); } public function offsetGet($var) { var_dump(__METHOD__); return "value"; }}$obj = new obj;echo "Runs obj::offsetExists()\n";var_dump(isset($obj["foobar"]));echo "\nRuns obj::offsetExists() and obj::offsetGet()\n";var_dump(empty($obj["foobar"]));echo "\nRuns obj::offsetExists(), *not* obj:offsetGet() as there is nothing to get\n";var_dump(empty($obj["foobaz"]));?>
The above example will output something similar to:
Runs obj::offsetExists() string(17) "obj::offsetExists" bool(true) Runs obj::offsetExists() and obj::offsetGet() string(17) "obj::offsetExists" string(14) "obj::offsetGet" bool(false) Runs obj::offsetExists(), *not* obj:offsetGet() as there is nothing to get string(17) "obj::offsetExists" bool(true)
