is_countable

(PHP 7 >= 7.3.0)

is_countable Verify that the contents of a variable is a countable value

说明

is_countable ( mixed $var ) : bool

Verify that the contents of a variable is an array or an object implementing Countable

参数

var

The value to check

返回值

Returns TRUE if var is countable, FALSE otherwise.

更新日志

版本 说明
7.3.0 is_countable() has been added.

范例

Example #1 is_countable() examples

<?php
var_dump
(is_countable([123])); // bool(true)
var_dump(is_countable(new ArrayIterator(['foo''bar''baz']))); // bool(true)
var_dump(is_countable(new ArrayIterator())); // bool(true)
var_dump(is_countable(new stdClass())); // bool(false)

参见

add a note add a note

User Contributed Notes 4 notes

up
22
info at arisendrake dot de
1 year ago
If you are unable to upgrade to PHP 7.3 (not released at the time of writing), you can use this simple polyfill:

<?php
if (!function_exists('is_countable')) {
    function
is_countable($var) {
        return (
is_array($var) || $var instanceof Countable);
    }
}
?>
up
2
danmichaelo at gmail dot com
7 months ago
Note that a polyfill for this method is also provided by the symfony/polyfill project.
up
0
renic
4 months ago
be wary of using is_object($var) and assuming that the object has implemented Countable.  Not all objects are countable directly with count().
up
-3
deoomen
7 months ago
Polyfill written by arisendrake is not quite good. It return FALSE when checking an Simple XML Node but count() works properly on PHP 7.1 and 7.3.
Better is this one:

<?php
if (version_compare(PHP_VERSION, "7.3") < 0 && !function_exists("is_countable")) {
    function
is_countable($var): bool
   
{
        return (
is_array($var) || is_object($var) || is_iterable($var) || $var instanceof Countable);
    }
}
?>
To Top