Question

I have strings that are formatted as below:

“Houston, TX” – str1
“Chicago, IL” – str2
“Seattle, WA” – str3

i want to extract “TX”, “IL”, “WA” when given each of the above str1/str2/str3, if a state code exists in string (i.e. 2 upper case letters at end of string) using PHP & regex.. any pointers.. i am unable to reliably extract this info from all the strings given to my method.

Answer 1

You don’t need to use regular expressions for this. Assuming the state code can only appear at the very end of a string, you can use this small function:

/**
 * Extracts the US state code from a string and returns it, otherwise
 * returns false.
 *
 * "Houston, TX" - returns "TX"
 * "TX, Houston" - returns false
 *
 * @return string|boolean
 */
function getStateCode($string)
{
    // I'm not familiar with all the state codes, you
    // should add them yourself.
    $codes = array('TX', 'IL', 'WA');

    $code = strtoupper(substr($string, -2));

    if(in_array($code, $codes))
    {
        return $code;
    }
    else
    {
        return false;
    }
}