PHP will generally correctly guess the data type you intend to use from the context it’s used in, however sometimes it is useful to manually force a type. This can be accomplished by prefixing the declaration with the name of the required type in parenthesis:
$bool = true;
var_dump($bool); // bool(true)
$int = (int) true;
var_dump($int); // int(1)
$string = (string) true;
var_dump($string); // string(1) "1"
$string = (string) false;
var_dump($string); // string(0) ""
$float = (float) true;
var_dump($float); // float(1)
$array = ['x' => 'y'];
var_dump((object) $array); // object(stdClass)#1 (1) { ["x"]=> string(1) "y" }
$object = new stdClass();
$object->x = 'y';
var_dump((array) $object); // array(1) { ["x"]=> string(1) "y" }
$string = "asdf";
var_dump((unset)$string); // NULL
But be carefull: not all type casts work as one might expect:
// below 3 statements hold for 32-bits systems (PHP_INT_MAX=2147483647)
// an integer value bigger than PHP_INT_MAX is automatically converted to float:
var_dump( 999888777666 ); // float(999888777666)
// forcing to (int) gives overflow:
var_dump((int) 999888777666 ); // int(-838602302)
// but in a string it just returns PHP_INT_MAX
var_dump((int) "999888777666"); // int(2147483647)
var_dump((bool) []); // bool(false) (empty array)
var_dump((bool) [false]); // bool(true) (non-empty array)
Found a mistake? Have a question or improvement idea?
Let me know.