CustomHashArray

Create you own associative arrays in PHP with custom key matching

For a convenient, single-class version of a case insensitive implimentation see CaseInsensitiveArray

Usage

Creating a custom whitespace-insensitive array class. Only one method is required: hash($key)

class WhitespaceInsensitiveArray extends CustomHashArray {
    protected function hash($key) {
        return preg_replace('/\s/', '', $key);
    }
}

Using the newly created class

$arr = new WhitespaceInsensitiveArray;
$arr['Hello'."\n".'World'] = 'hi';

echo $arr['Hello    World'];
// Outputs: hi

$arr['other'] = 'Other thing';
$arr['HelloWorld'] = 'Same hash';

foreach ($arr as $key => $value) {
    echo $key.' => '.$value."\n";
}
// Outputs:
//   other => Other thing
//   HelloWorld => Same hash

Behaviour

Key access is controlled by a hash. When accessing the array's keys they will be returned as the original key that defined them.

If an existing hash is overwritten with a different key the new key will be used when returning key names.