问题描述
我有很多函数要么对数组有类型提示,要么使用 is_array()
来检查变量的数组。
I have a lot of functions that either have type hinting for arrays or use is_array()
to check the array-ness of a variable.
现在我开始使用可迭代的对象了。它们实现 Iterator
或 IteratorAggregate
。如果它们通过类型提示,或者经过 is_array()
,它们会被接受为数组吗?
Now I'm starting to use objects that are iterable. They implement Iterator
or IteratorAggregate
. Will these be accepted as arrays if they pass through type hinting, or undergo is_array()
?
如果我必须修改我的代码,是否有一般的 is_iterable()
,或者我必须做类似于:
If I have to modify my code, is there a generic sort of is_iterable()
, or must I do something like:
if ( is_array($var) OR $var instance_of Iterable OR $var instanceof IteratorAggregate ) { ... }
还有哪些可迭代的接口?
What other iterable interfaces are out there?
推荐答案
我认为你的意思是instanceof Iterator
,PHP没有 Iterable
界面。它确实有一个 Traversable
接口虽然。 Iterator
和 IteratorAggregate
都延伸 Traversable
(和AFAIK他们是是唯一这样做的。)
I think you mean instanceof Iterator
, PHP doesn't have an Iterable
interface. It does have a Traversable
interface though. Iterator
and IteratorAggregate
both extend Traversable
(and AFAIK they are the only ones to do so).
但不,实现 Traversable
的对象不会传递 is_array()
检查,也没有内置的 is_iterable()
函数。你可以使用的支票是
But no, objects implementing Traversable
won't pass the is_array()
check, nor there is a built-in is_iterable()
function. A check you could use is
function is_iterable($var) {
return (is_array($var) || $var instanceof Traversable);
}
要清楚,所有 php对象都可以使用foreach迭代,但只有某些实现 Traversable
。因此,所提供的 is_iterable
函数不会检测到foreach可以处理的所有内容。
To be clear, all php objects can be iterated with foreach, but only some of them implement Traversable
. The presented is_iterable
function will therefore not detect all things that foreach can handle.
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