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) || $var instanceof Countable);
}
}
?>
is_countable
(PHP 7 >= 7.3.0)
is_countable — Verify that the contents of a variable is a countable value
Parametry
-
var -
The value to check
Zwracane wartości
Returns TRUE if var is countable, FALSE
otherwise.
Rejestr zmian
| Wersja | Opis |
|---|---|
| 7.3.0 | is_countable() has been added. |
Przykłady
Przykład #1 is_countable() examples
<?php
var_dump(is_countable([1, 2, 3])); // bool(true)
var_dump(is_countable(new ArrayIterator(['foo', 'bar', 'baz']))); // bool(true)
var_dump(is_countable(new ArrayIterator())); // bool(true)
var_dump(is_countable(new stdClass())); // bool(false)
Zobacz też:
- is_array() - Finds whether a variable is an array
- is_object() - Finds whether a variable is an object
- is_iterable() - Verify that the contents of a variable is an iterable value
- is_bool() - Finds out whether a variable is a boolean
add a note
User Contributed Notes 6 notes
info at arisendrake dot de ¶
5 years ago
renic ¶
4 years ago
be wary of using is_object($var) and assuming that the object has implemented Countable. Not all objects are countable directly with count().
Anonymous ¶
3 years ago
Fixed polyfill:
<?php
if (! function_exists('is_countable')) {
/**
* @param mixed $value The value to check
* @return bool
*/
function is_countable($value): bool
{
return is_array($value) || (is_object($value) && $value instanceof Countable);
}
}
?>
info at ensostudio dot ru ¶
3 years ago
Note: if is_countable() return true is does not guarantee that the it can be calculated recursively and correctly:
<?php
$iterator = new ArrayIterator(['one', 'two', new ArrayIterator(['three', 'four'])]);
var_dump(is_countable($iterator), count($iterator, COUNT_RECURSIVE));
// return TRUE and 3!
?>
danmichaelo at gmail dot com ¶
5 years ago
Note that a polyfill for this method is also provided by the symfony/polyfill project.
deoomen ¶
5 years ago
Polyfill written by arisendrake is not quite good. It return FALSE when checking an Simple XML Node but count() works properly on PHP 7.1 and 7.3.
Better is this one:
<?php
if (version_compare(PHP_VERSION, "7.3") < 0 && !function_exists("is_countable")) {
function is_countable($var): bool
{
return (is_array($var) || is_object($var) || is_iterable($var) || $var instanceof Countable);
}
}
?>
