PHP aggregate iterator interface IteratorAggregate usage analysis,

PHP aggregate iterator interface IteratorAggregate usage analysis,

This article describes the usage of the PHP aggregate iterator interface IteratorAggregate. We will share this with you for your reference. The details are as follows:

PHP IteratorAggregate is also called an aggregate iterator. It provides an interface for creating an external iterator. The interface abstract is as follows:

IteratorAggregate extends Traversable {  abstract public Traversable getIterator ( void )}

When implementing the getIterator method, you must return an instance of classes that implement the Iterator interface.

Example:

<? Php/*** use the aggregate iterator, return an instance of the class implementing the Iterator interface ** @ author crazy old driver */class myData implements IteratorAggregate {public $ one = "Public property one "; public $ two = "Public property two"; public $ three = "Public property three"; public function _ construct () {$ this-> last = "last property ";} public function getIterator () {return new ArrayIterator ($ this) ;}}$ obj = new myData; foreach ($ obj as $ key =>$ value ) {Var_dump ($ key, $ value); echo '<br>'; // Linux: echo "\ n" ;}?>

Output of the preceding example:

string 'one' (length=3)string 'Public property one' (length=19)string 'two' (length=3)string 'Public property two' (length=19)string 'three' (length=5)string 'Public property three' (length=21)string 'last' (length=4)string 'last property' (length=13)

The ArrayIterator iterator encapsulates objects or arrays as a class that can be operated through foreach. For details, refer to the introduction of the SPL iterator. For more information, see http://www.bkjia.com/article/41074.htm.