FUDforum: comp.lang.php » ArrayAccess interface, Traversable interface and foreach

Home » Imported messages » comp.lang.php » ArrayAccess interface, Traversable interface and foreach

Show: Today's Messages :: Unread Messages :: Polls :: Message Navigator
| Subscribe to topic | Bookmark topic

ArrayAccess interface, Traversable interface and foreach [message #185987]

Fri, 23 May 2014 14:22

kurtk(at)pobox(dot)com
Messages: 10
Registered: May 2012

Karma: 0

Junior Member

add to buddy list
ignore all messages by this user

The documentation for ArrayAccess (at http://www.php.net/manual/en/class.arrayaccess.php) doesn't show it implementing Traversable. Nevertheless, you can still use any class you write that implements ArrayAccess in a foreach loop.

This seems like an oversight in the documentation--unless I am missing something?

Report message to a moderator

Rate author: +1 -1

Message by Jerry Stuckle is ignored [reveal message] [reveal all messages by Jerry Stuckle] [stop ignoring this user]

Message by Christoph Michael Bec is ignored [reveal message] [reveal all messages by Christoph Michael Bec] [stop ignoring this user]

Message by Jerry Stuckle is ignored [reveal message] [reveal all messages by Jerry Stuckle] [stop ignoring this user]

Message by Christoph Michael Bec is ignored [reveal message] [reveal all messages by Christoph Michael Bec] [stop ignoring this user]

Re: ArrayAccess interface, Traversable interface and foreach [message #185996 is a reply to message #185989]

Tue, 27 May 2014 14:59

Adam Harvey
Messages: 25
Registered: September 2010

Karma: 0

Junior Member

add to buddy list
ignore all messages by this user

On Sat, 24 May 2014 12:05:02 +0200, Christoph Michael Becker wrote:

> kurtk(at)pobox(dot)com wrote:
>
>> This seems like an oversight in the documentation--unless I am missing
>> something?
>
> You can use any object (whether it is an instance of a class that
> implements Traversable or not) in a foreach loop, see
> <http://www.php.net/manual/en/control-structures.foreach.php>.

Yep, this is why objects that implement ArrayAccess still work with
foreach without implementing Traversable.

ArrayAccess and Traversable are technically different things: Traversable
provides a way to control iteration, whereas ArrayAccess is only for
array-style dereferencing via $object['key']. In practice, classes that
need to imitate arrays will need to implement both (probably by extending
a class such as ArrayObject that implements both interfaces).

Adam

Report message to a moderator

Rate author: +1 -1

Re: ArrayAccess interface, Traversable interface and foreach [message #186028 is a reply to message #185989]

Mon, 02 June 2014 10:15

kurtk(at)pobox(dot)com
Messages: 10
Registered: May 2012

Karma: 0

Junior Member

add to buddy list
ignore all messages by this user

> You can use any object (whether it is an instance of a class that
>
> implements Traversable or not) in a foreach loop, see
> <http://www.php.net/manual/en/control-structures.foreach.php>.

Thanks Christoph. I didn't realize that any object can be used in a foreach loop, and that it doesn't need to implement an interface that derives from Traversable.

Report message to a moderator

Rate author: +1 -1