In PHP, how can I convert an Excel style column name into a number?

Question

Using PHP, how can I convert an Excel style column name, like "CF", into a number (CF=84)? This question specifically pertains to PHP. Please don't "dupe" this with an answer for a different language.

Answer 1

Try these functions.

/**
 * Convert Excel style column names into numbers.
 * @param string $column Excel style column name like AA or CF
 * @return integer Number with A being 1 and AA being 27
 */

function alpha2num($column) {
    $number = 0;
    foreach(str_split($column) as $letter){
        $number = ($number * 26) + (ord(strtolower($letter)) - 96);
    }
    return $number;
}

/**
 * Access array value with Excel style column name.
 * @param array $array The array to access
 * @param string $column Excel style column name like AA or CF
 * @return mixed Value found at the column
 */
function alpha_col($array, $column){
    $i = alpha2num($column) - 1;
    return isset($array[$i]) ? $array[$i] : false;
}