php 格式化电话号码

只适用于美国电话号码

function format_phone($phone) {    $phone = preg_replace("/[^0-9]/", "", $phone);    if(strlen($phone) == 7)        return preg_replace("/([0-9]{3})([0-9]{4})/", "$1-$2", $phone);    elseif(strlen($phone) == 10)        return preg_replace("/([0-9]{3})([0-9]{3})([0-9]{4})/","($1) $2-$3",$phone);    else        return $phone;}