_my_number = $number; $this->_my_letter = $letter; } function getNumber() { return $this->_my_number; } function getLetter() { return $this->_my_letter; } function setNumb($number) { $this->_my_number = $number; } function __toString() { return "{$this->getNumber()}"; } } /* To enable key=>value iteration, we must override the default key() * method in Structures_LinkedList_Double to return a meaningful value */ class LinkListTester extends Structures_LinkedList_Double { function key() { return $this->current()->getLetter(); } } /* Now we'll create some instances of the new class */ $node1 = new LinkNodeTester(1, 'a'); $node2 = new LinkNodeTester(2, 'b'); $node3 = new LinkNodeTester(3, 'c'); $node4 = new LinkNodeTester(4, 'd'); $node5 = new LinkNodeTester(5, 'e'); /* Start by instantiating a list object. * You can either pass the first node to the constructor, * or leave it null and add nodes later. */ $list = new LinkListTester($node1); // 1 /* appendNode() adds a node to the end of the list */ $list->appendNode($node2); // 1-2 /* prependNode() adds a node to the start of the list */ $list->prependNode($node3); // 3-1-2 /* insertNode($new_node, $reference_node, $before) adds a node * before the reference node if the third parameter is true, * or after the reference node if the third parameter is false */ $list->insertNode($node4, $node1); // 3-1-4-2 $list->insertNode($node5, $node1, true); // 3-5-1-4-2 /* current() returns the current pointer node in the list */ $link = $list->current(); print $link->getNumber(); // "1" /* rewind() resets the pointer to the root node of the list */ $link = $list->rewind(); print $link->getNumber(); // "3" // iterate through the list with do...while() do { print $link->getNumber(); } while ($link = $list->next()); // "35142" /* You can also iterate through a list with foreach() */ foreach ($list as $bull) { print $bull->getNumber(); } // 3-1-4-2 /* Override the key() method to enable $key=>$value iteration */ foreach ($list as $key=>$value) { print "$key => $value\n"; } /* end() resets the pointer to the last node of the list */ $link = $list->end(); print $link->getNumber(); // "2" /* You can iterate backwards through a list with previous() */ do { print $link->getNumber(); } while ($link = $list->previous()); // "24153" ?>