Is it possible to overload operators in PHP?

Specifically, I would like to create an Array class and would like to overload the [] operator.

If you are using PHP5 (and you should be), take a look at the SPL ArrayObject classes. The documentation isn't too good, but I think if you extend ArrayObject, you'd have your "fake" array.

EDIT: Here's my quick example; I'm afraid I don't have a valuable use case though:

class a extends ArrayObject {
    public function offsetSet($i, $v) {
        echo 'appending ' . $v;
        parent::offsetSet($i, $v);
    }
}

$a = new a;
$a[] = 1;

Actually, the optimal solution is to implement the four methods of the ArrayAccess interface: http://php.net/manual/en/class.arrayaccess.php

If you would also like to use your object in the context of 'foreach', you'd have to implement the 'Iterator' interface: http://www.php.net/manual/en/class.iterator.php

PHP's concept of overloading and operators (see Overloading, and Array Operators) is not like C++'s concept. I don't believe it is possible to overload operators such as +, -, [], etc.

Possible Solutions

• Implement SPL ArrayObject (as mentioned by cbeer).
• Implement Iterator (if ArrayObject is too slow for you).
• Use the PECL operator extension (as mentioned by Benson).

For a simple and clean solution in PHP 5.0+, you need to implements the ArrayAccess interface and override functions offsetGet, offsetSet, offsetExists and offsetUnset. You can now use the object like an array.

Example (in PHP7+):

<?php
class A implements ArrayAccess {
	private $data = [];

	public function offsetGet($offset) {
		return $this->data[$offset] ?? null;
	}

	public function offsetSet($offset, $value) {
		if ($offset === null) {
			$this->data[] = $value;
		} else {
			$this->data[$offset] = $value;
		}
	}

	public function offsetExists($offset) {
		return isset($this->data[$offset]);
	}

	public function offsetUnset($offset) {
		unset($this->data[$offset]);
	}
}

$obj = new A();
$obj[] = 'a';
$obj['k'] = 'b';
echo $obj[0], $obj['k']; // print "ab"

It appears not to be a feature of the language, see this bug. However, it looks like there's a package that lets you do some sort of overloading.

Put simply, no; and I'd suggest that if you think you need C++-style overloading, you may need to rethink the solution to your problem. Or maybe consider not using PHP.

To paraphrase Jamie Zawinski, "You have a problem and think, 'I know! I'll use operator overloading!' Now you have two problems."