is_iterable

(PHP 7 >= 7.1.0)

is_iterable — Verify that the contents of a variable is an iterable value

说明

is_iterable ( mixed $var ) : bool

Verify that the contents of a variable is accepted by the iterable pseudo-type, i.e. that it is either an array or an object implementing Traversable

参数

var

The value to check

返回值

Returns TRUE if var is iterable, FALSE otherwise.

范例

Example #1 is_iterable() examples

<?php

var_dump(is_iterable([1, 2, 3]));  // bool(true)
var_dump(is_iterable(new ArrayIterator([1, 2, 3])));  // bool(true)
var_dump(is_iterable((function () { yield 1; })()));  // bool(true)
var_dump(is_iterable(1));  // bool(false)
var_dump(is_iterable(new stdClass()));  // bool(false)

?>

参见

User Contributed Notes

mopsyd at me dot com 01-Apr-2018 04:24
A slight correction to brcontainer's polyfill, which prevents errors on a non-object in a non-blocking way, and also corrects the issue of  the conditional checking "file_exists" instead of the correct "function_exists":

if ( !function_exists(  'is_iterable' ) )
{

    function is_iterable( $obj )
    {
        return is_array( $obj ) || ( is_object( $obj ) && ( $obj instanceof \Traversable ) );
    }

}

The original answer would not have resolved correctly, because it was looking for a file instead of a function, and the provided method would error if given a non-iterable non-object value such as false.
brcontainer at yahoo dot com dot br 09-Mar-2018 08:35
Polyfill for PHP5.6 and PHP7.0

    if (!file_exists('is_iterable')) {
        function is_iterable($obj)
        {
            return is_array($obj) || $obj instanceof \Traversable;
        }
    }
anatoly dot pashin at gmail dot com 01-Feb-2018 07:02
Here is more details on iterable type: http://php.net/manual/en/language.types.iterable.php