ArrayAccess::offsetExists
PHP function
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(PHP 5, PHP 7, PHP 8)
Whether an offset exists
Description
ArrayAccess::offsetExists(mixed $offset): bool
Whether or not an offset exists.
This method is executed when using isset() or empty() on objects implementing ArrayAccess.
Note
When using empty() ArrayAccess::offsetGet() will be called and checked if empty only if ArrayAccess::offsetExists() returns true.
Parameters
offsetAn offset to check for.
Return Values
Success
Note
The return value will be casted to bool if non-boolean was returned.
Examples
ArrayAccess::offsetExists() example
php
<?php
class obj implements ArrayAccess {
public function offsetSet($offset, $value): void {
var_dump(__METHOD__);
}
public function offsetExists($var): bool {
var_dump(__METHOD__);
if ($var == "foobar") {
return true;
}
return false;
}
public function offsetUnset($var): void {
var_dump(__METHOD__);
}
#[\ReturnTypeWillChange]
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:
output
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)