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PHP - Manual: is_iterable

2024-11-14

is_iterable

(PHP 7 >= 7.1.0, PHP 8)

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

说明

is_iterable(mixed $value): 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

value

The value to check

返回值

Returns true if value is iterable, false otherwise.

范例

示例 #1 is_iterable() examples

<?php

var_dump
(is_iterable([123]));  // bool(true)
var_dump(is_iterable(new ArrayIterator([123])));  // 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

add a noteadd a note

User Contributed Notes 3 notes

up
26
mopsyd at me dot com
4 years ago
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.
up
-18
brcontainer at yahoo dot com dot br
4 years ago
Polyfill for PHP5.6 and PHP7.0

    if (!file_exists('is_iterable')) {
        function is_iterable($obj)
        {
            return is_array($obj) || $obj instanceof \Traversable;
        }
    }

官方地址:https://www.php.net/manual/en/function.is-iterable.php

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