- Accessing All Elements of Numeric Arrays
- Accessing All Elements of Associative Arrays
- Accessing All Array Elements in Nested Arrays
- Turning an Array into Variables
- Converting Strings to Arrays
- Converting Arrays to Strings
- Sorting Arrays Alphabetically
- Sorting Associative Arrays Alphabetically
- Sorting Nested Arrays
- Sorting Nested Associative Arrays
- Sorting IP Addresses (as a Human Would)
- Sorting Anything
- Sorting with Foreign Languages
- Applying an Effect to All Array Elements
- Filtering Arrays
- Getting Random Elements Out of Arrays
- Making Objects Behave Like Arrays
This chapter is from the book
This chapter is from the book
This chapter is from the book
Making Objects Behave Like Arrays
class MyArray implements ArrayAccess, Countable
<?php
class MyArray implements ArrayAccess, Countable {
private $_data = array();
/* ArrayAccess interface */
public function offsetSet($offset, $value) {
$this->_data[$offset] = $value;
}
public function offsetExists($offset) {
return isset($this->_data[$offset]);
}
public function offsetUnset($offset) {
unset($this->_data[$offset]);
}
public function offsetGet($offset) {
//return (isset($this->_data[$offset])) ? $this->_data[$offset] : null;
return ($this->offsetExists($offset)) ? $this->_data[$offset] : null;
}
/* Countable Interface */
public function count() {
return count($this->_data);
}
}
$a = new MyArray();
$a[0] = 'I';
$a[1] = 'II';
$a[2] = 'III';
$a[3] = 'IV';
for ($i = 0; $i < count($a); $i++) {
printf('<p>%s</p>', htmlspecialchars($a[$i]));
}
?>
Using an Object Like an Array with SPL (splArray.php)
SPL, the Standard PHP Library, is one of the most underrated features of PHP. It basically offers a huge set of interfaces. If you create a class using one of those interfaces, you might use standard PHP functions with your class. The documentation at http://php.net/spl is not always as detailed as you would expect, but it does give you some great pointers as to what is possible.
As a simple example, we will create a class (you can find more about various aspects of object-oriented programming [OOP] in Chapter 4) that implements two interfaces:
- ArrayAccess—Allows accessing individual elements within the object’s collection (in our code, a simple array)
- Countable—Allows calling count() on an object instance
If you want full array support, you need to implement additional interfaces, including Iterable (for iterator support; for example, via foreach) and some more. The ArrayObject interface aggregates several of the required interfaces, which in turn could even allow advanced features like user-defined sorting.