The Traversable interface
Guide
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Interface to detect if a class is traversable using Foreach.
Intro
Interface to detect if a class is traversable using Foreach.
Abstract base interface that cannot be implemented alone. Instead, it must be implemented by either IteratorAggregate or Iterator.
Interfacesynopsis
implements Traversable { }
This interface has no methods; its only purpose is to be the base interface for all traversable classes.
Changelog
| Version | Description |
|---|---|
| 8.0.0 | The Traversable interface can now be implemented by abstract classes. Extending classes must implement Iterator or IteratorAggregate. |
Notes
Note
Internal (built-in) classes that implement this interface can be used in a Foreach construct and do not need to implement IteratorAggregate or Iterator.
Note
Prior to PHP 8.0.0, this internal engine interface couldn't be directly implemented in PHP scripts — not even by abstract classes. Either IteratorAggregate or Iterator must be used instead.