IteratorAggregate interface in PHP - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to implement the IteratorAggregate interface in the class.

PHP

<?php
class MyCollection implements IteratorAggregate {
    private array $items = [];

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

    public function [1]() {
        return new ArrayIterator($this->items);
    }
}
?>

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AgetItems

BfetchIterator

CgetIterator

Diterator

Attempts:

3 left

💡 Hint

Common Mistakes

Using a method name other than getIterator.

Not returning an iterator object.

The IteratorAggregate interface requires implementing the getIterator() method which returns an iterator.

2fill in blank

medium

Complete the code to return an iterator over the items array.

PHP

<?php
public function getIterator() {
    return new [1]($this->items);
}
?>

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ATraversable

BIteratorAggregate

CIterator

DArrayIterator

Attempts:

3 left

💡 Hint

Common Mistakes

Using interface names instead of a concrete iterator class.

Returning the array directly instead of an iterator.

ArrayIterator is a built-in class that implements Iterator and can iterate over arrays.

3fill in blank

hard

Fix the error in the method signature to properly implement IteratorAggregate.

PHP

<?php
class Collection implements IteratorAggregate {
    public function [1](): Traversable {
        // method body
    }
}
?>

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AgetIterator

Biterator

CgetItems

DfetchIterator

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect method names.

Omitting the return type declaration.

The method must be named getIterator and return a Traversable to satisfy the interface.

4fill in blank

hard

Fill both blanks to create a class that implements IteratorAggregate and returns an iterator over a private array.

PHP

<?php
class [1] implements IteratorAggregate {
    private array $data;

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

    public function getIterator(): [2] {
        return new ArrayIterator($this->data);
    }
}
?>

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ADataCollection

BTraversable

CIterator

DArrayAccess

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect return types.

Choosing unrelated class names.

The class name can be any valid name like DataCollection. The getIterator method must return Traversable.

5fill in blank

hard

Fill all three blanks to create a class that implements IteratorAggregate, stores items, and returns an iterator.

PHP

<?php
class [1] implements IteratorAggregate {
    private array $[2];

    public function __construct(array $items) {
        $this->[2] = $items;
    }

    public function getIterator(): [3] {
        return new ArrayIterator($this->[2]);
    }
}
?>

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AItemList

Bitems

CTraversable

Ddata

Attempts:

3 left

💡 Hint

Common Mistakes

Mismatching property names.

Incorrect return type for getIterator.

The class name is ItemList, the private property is items, and getIterator returns Traversable.