check string for zip code

[webabolic]

I want to check a string to see if it contains a zip code. I think I need to use preg_match or ereg to execute this task.

//////Some examples strings that will be checked:

San Francisco, CA 94109

Los Angeles, California 90210

San Diego ca 91025

////////Other Notes
Zip codes are 5 digits in length

If the zip code is in the string I would like to return it as a variable called $search_zip

Thanks

[devinemke]

$string = 'San Francisco, CA 94109';

$explode = explode(' ' , $string);
foreach ($explode as $value)
{
	if (strlen($value) == 5 && is_numeric($value))
	{
		echo 'there appears to be a zip code in this string: ' . $value;
	}
}