is_iterable
(PHP 7 >= 7.1.0, PHP 8)
is_iterable — Verify that the contents of a variable is an iterable value
说明
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([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)
?>
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User Contributed Notes 3 notes
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 ) && ( $obj instanceof \Traversable ) );
}
}
The original answer would not have resolved correctly, because it was looking for a file instead of a function, and the provided method would error if given a non-iterable non-object value such as false.
anatoly dot pashin at gmail dot com ¶
4 years ago
Here is more details on iterable type: http://php.net/manual/en/language.types.iterable.php
brcontainer at yahoo dot com dot br ¶
4 years ago
Polyfill for PHP5.6 and PHP7.0
if (!file_exists('is_iterable')) {
function is_iterable($obj)
{
return is_array($obj) || $obj instanceof \Traversable;
}
}