Dutch PHP Conference 2019

is_countable

(PHP 7 >= 7.3.0)

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

说明

bool is_countable ( mixed $var )

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

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User Contributed Notes 1 note

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1
info at arisendrake dot de
2 months 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);
    }
}
?>
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