How to detect if object is Traversable in PHP?

Question

How can I detect the variable is a Traversable object to use in foreach loops?

if(is_traversable($variable)) {
    return (array) $variable;
}

Answer 1

is_iterable can be used since PHP 7.1.

// https://wiki.php.net/rfc/iterable
var_dump(
    true === is_iterable([1, 2, 3]),
    true === is_iterable(new ArrayIterator([1, 2, 3])),
    true === is_iterable((function () { yield 1; })())
);

Answer 2

Use instanceof to determine if the object is Traversable

if($variable instanceof \Traversable) {
  // is Traversable
}