PHP 8.4.0 Alpha 2 available for testing

is_iterable

(PHP 7 >= 7.1.0, PHP 8)

is_iterable 验证变量的内容是否为可迭代值

说明

is_iterable(mixed $value): bool

验证变量的内容是否被 iterable 伪类型接受,即不是 array,就是实现了 Traversable 接口的对象。

参数

value

验证的值

返回值

如果 value 可迭代返回 true,否则返回 false

示例

示例 #1 is_iterable() 示例

<?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

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User Contributed Notes 3 notes

up
34
mopsyd at me dot com
6 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
-28
brcontainer at yahoo dot com dot br
6 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;
}
}
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