PHP pre-defined interface one: traversable

The traversable is used to detect whether a class can traverse using foreach.

• This is an internal engine interface that cannot be implemented in PHP scripts, and we use the iterator interface or the Iteratoraggregate interface to implement traversal in practical programming.
• There is no method for this interface, and it serves only as a basic interface for all the traversed classes.

Interface Summary

Traversable {}

Code Demo :

$arr = [1, 2, 3, 4];$obj = (object)$arr;if ($arr instanceof \Traversable) {    echo ‘arr is Traversable‘ . PHP_EOL;} else {    echo ‘arr is not Traversable‘ . PHP_EOL;}if ($obj instanceof \Traversable) {    echo ‘obj is Traversable‘ . PHP_EOL;} else {    echo ‘obj is not Traversable‘ . PHP_EOL;}// arr和obj不是implement Traversable

PHP pre-defined interface one: traversable