Using array function on an object

In PHP is it possible for the array fun开发者_运维技巧ctions such as array_values() and array_key_exists() to be used on an object ?

array_key_exists() used to work for objects, but as of PHP 5.3.0, it doesn't anymore. You should use property_exists() instead.

PHP objects can be cast to an array without a method call and with virtually no performance penalty, which will allow you to use any array function you like on the properties.

$arr = (array) $obj;

Using language constructs is almost always substantially faster in PHP than calling a method. isset is considered a language construct.

I realise this has a faint whiff of premature optimisation, but the result of running the following code in PHP 5.3 may surprise you.

<?php
$count = 50000;

class Pants
{
    public $mega='wad';
    public $pung=null;
}

$s = microtime(true);
for ($i=0; $i < $count; $i++) {
    $p = new Pants;
    $e = property_exists($p, 'mega');
    $e = property_exists($p, 'pung');
}
var_dump(microtime(true) - $s);

$s = microtime(true);
for ($i=0; $i < $count; $i++) {
    $p = new Pants;
    $p = get_object_vars($p);
    $e = isset($p['mega']);
    $e = isset($p['pung']);
}
var_dump(microtime(true) - $s);

$s = microtime(true);
for ($i=0; $i < $count; $i++) {
    $p = new Pants;
    $p = (array) $p;
    $e = isset($p['mega']);
    $e = isset($p['pung']);
}
var_dump(microtime(true) - $s);

Output:

float(0.27921605110168)
float(0.22439503669739)
float(0.092200994491577)

This clearly demonstrates that the best way to do these kinds of gymnastics in PHP is to rely on whichever method uses the most first-class language constructs and the fewest method calls and the best one I've found is the (array) cast.

For the case of array_values(), use get_object_vars() to get its public properties (depends on the scope of the client code, if you want to obtain protected and private properties).

If you want something more OO, ReflectionObject can do quite a lot.

If you absolutely need the functionality in array_values and array_keys, you can do this: $keys = array_keys(get_object_vars($obj)) and $values = array_values(get_object_vars($obj))

A better and more OO way would be to create an interface with methods for keys and values. Then implement those methods in your class to get the keys and values. Other array-like interfaces are neatly presented in ArrayIterator class.