What are iterators

Iterators are objects in programming that allow for sequential access to elements in a collection without exposing the underlying structure of that collection. They enable the iteration over complex data structures like arrays, lists, and more, making it easier to manipulate data by providing a simple interface for traversal.

In PHP, iterators provide a standard way of traversing collections, allowing developers to build custom iterator classes or use built-in iterator classes. Understanding iterators is essential in creating efficient and maintainable code.


        <?php
        class MyIterator implements Iterator {
            private $items = [];
            private $currentIndex = 0;

            public function __construct($items) {
                $this->items = $items;
            }

            public function current() {
                return $this->items[$this->currentIndex];
            }

            public function key() {
                return $this->currentIndex;
            }

            public function next() {
                ++$this->currentIndex;
            }

            public function rewind() {
                $this->currentIndex = 0;
            }

            public function valid() {
                return isset($this->items[$this->currentIndex]);
            }
        }

        $items = [1, 2, 3, 4, 5];
        $iterator = new MyIterator($items);

        foreach ($iterator as $key => $value) {
            echo "Key: $key; Value: $value\n";
        }
        ?>

What are iterators

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What are iterators

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