PHP实例说明编写PHP代码的5个好习惯

<?

function getNBDay($d){    switch($d) {        case 5:        case 6:        case 7:            return 1;        default:            return ($d + 1);    }}

$day = 5;

$nextDay = getNBDay($day);

echo ("Next day is: " . $nextDay . "\n");

?>

<?

define ('MONDAY', 1);define ('TUESDAY', 2);define ('WEDNESDAY', 3);define ('THURSDAY', 4);define ('FRIDAY', 5);define ('SATURDAY', 6);define ('SUNDAY', 7);

/* * * @param $dayOfWeek * @return int Day of week, with 1 being Monday and so on. */function findNextBusinessDay($dayOfWeek){    $nextBusinessDay = $dayOfWeek;

switch($dayOfWeek) {        case FRIDAY:        case SATURDAY:        case SUNDAY:            $nextBusinessDay = MONDAY;            break;        default:            $nextBusinessDay += 1;            break;    }

return $nextBusinessDay;}

$day = FRIDAY;

$nextBusDay = findNextBusinessDay($day);

echo ("Next day is:" . $nextBusDay . "\n");

?>

<?

function writeRssFeed($user){    // Get the DB connection information

// look up the user's preferences...    $link = mysql_connect('mysql_host', 'mysql_user', 'mysql_password')        OR die(mysql_error());

// Query    $perfsQuery = sprintf("SELECT max_stories FROM user_perfs WHERE user= '%s'",            mysql_real_escape_string($user));

$result = mysql_query($query, $link);

$max_stories = 25; // default it to 25;

if ($row = mysql_fetch_assoc($result)) {        $max_stories = $row['max_stories'];    }

// go get my data    $perfsQuery = sprintf("SELECT * FROM stories WHERE post_date = '%s'",            mysql_real_escape_string());

$result = mysql_query($query, $link); 

$feed = "<rss version=\"2.0\">" .        "<channel>" .        "<title>My Great Feed</title>" .        "<link>http://www.example.com/feed.xml</link>" .        "<description>The best feed in the world</description>" .        "<language>en-us</language>" .        "<pubDate>Tue, 20 Oct 2008 10:00:00 GMT</pubDate>" .        "<lastBuildDate>Tue, 20 Oct 2008 10:00:00 GMT</lastBuildDate>" .        "<docs>http://www.example.com/rss</docs>" .        "<generator>MyFeed Generator</generator>" .        "<managingEditor>editor@example.com</managingEditor>" .        "<webMaster>webmaster@example.com</webMaster>" .        "<ttl>5</ttl>";

// build the feed...        while ($row = mysql_fetch_assoc($result)) {            $title = $row['title'];            $link = $row['link'];            $description = $row['description'];            $date = $row['date'];            $guid = $row['guid'];

$feed .= "<item>";            $feed .= "<title>" . $title . "</title>";            $feed .= "<link>" . $link . "</link>";            $feed .= "<description> " . $description . "</description>";            $feed .= "<pubDate>" . $date . "</pubDate>";            $feed .= "<guid>" . $guid . "</guid>";            $feed .= "</item>";        }

$feed .= "</rss";

// write the feed out to the server...        echo($feed);

}

?>

<?

function createRssHeader(){    return "<rss version=\"2.0\">" .        "<channel>" .        "<title>My Great Feed</title>" .        "<link>http://www.example.com/feed.xml</link>" .        "<description>The best feed in the world</description>" .        "<language>en-us</language>" .        "<pubDate>Tue, 20 Oct 2008 10:00:00 GMT</pubDate>" .        "<lastBuildDate>Tue, 20 Oct 2008 10:00:00 GMT</lastBuildDate>" .        "<docs>http://www.example.com/rss</docs>" .        "<generator>MyFeed Generator</generator>" .        "<managingEditor>editor@example.com</managingEditor>" .        "<webMaster>webmaster@example.com</webMaster>" .        "<ttl>5</ttl>";}

function createRssFooter(){    return "</channel></rss>";}

function createRssItem($title, $link, $desc, $date, $guid) {    $item .= "<item>";    $item .= "<title>" . $title . "</title>";    $item .= "<link>" . $link . "</link>";    $item .= "<description> " . $description . "</description>";    $item .= "<pubDate>" . $date . "</pubDate>";    $item .= "<guid>" . $guid . "</guid>";    $item .= "</item>";    return $item;}

function getUserMaxStories($db_link, $default){    $perfsQuery = sprintf("SELECT max_stories FROM user_perfs WHERE user= '%s'",            mysql_real_escape_string($user));

$result = mysql_query($perfsQuery, $db_link);

$max_stories = $default;

if ($row = mysql_fetch_assoc($result)) {        $max_stories = $row['max_stories'];    } 

return $max_stories;}

function writeRssFeed($user){    // Get the DB connection information    $settings = parse_ini_file("rss_server.ini");

// look up the user's preferences...    $link = mysql_connect($settings['db_host'], $settings['user'],         $settings['password']) OR die(mysql_error());

$max_stories = getUserMaxStories($link, 25);

// go get my data    $newsQuery = sprintf("SELECT * FROM stories WHERE post_date = '%s'",            mysql_real_escape_string(time()));

$result = mysql_query($newsQuery, $link); 

$feed = createRssHeader();

$i = 0;    // build the feed...    while ($row = mysql_fetch_assoc($result)) {        if ($i < $max_stories) {            $title = $row['title'];            $link = $row['link'];            $description = $row['description'];            $date = $row['date'];            $guid = $row['guid'];

$feed .= createRssItem($title, $link, $description, $date, $guid);

$i++;        } else {             break;        }    }

mysql_close($link);

$feed .= createRssFooter();

// write the feed out to the server...    echo($feed);}?>

<?

class ResultMessage {    private $severity;    private $message;

public function __construct($sev, $msg)     {        $this->severity = $sev;        $this->message = $msg;    }

public function getSeverity()    {        return $this->severity;    }

public function setSeverity($severity)    {        $this->severity = $severity;    }

public function getMessage()    {        return $this->message;    }

public function setMessage($msg)    {        $this->message = $msg;    }}

function cntMsgs($messages){    $n = 0;    /* iterate through the messages... */    foreach($messages as $m) {        if ($m->getSeverity() == 'Error') {            $n++; // add one to the result;        }    }    return $n;}

$messages = array(new ResultMessage("Error", "This is an error!"),    new ResultMessage("Warning", "This is a warning!"),    new ResultMessage("Error", "This is another error!"));

$errs = cntMsgs($messages);

echo("There are " . $errs . " errors in the result.\n");

?>

<?/** * The ResultMessage class holds a message that can be returned * as a result of a process. The message has a severity and * message. *  * @author nagood * */class ResultMessage {    private $severity;    private $message;

/**     * Constructor for the ResultMessage that allows you to assign     * severity and message.     * @param $sev See {@link getSeverity()}     * @param $msg     * @return unknown_type     */    public function __construct($sev, $msg)     {        $this->severity = $sev;        $this->message = $msg;    }

/**     * Returns the severity of the message. Should be one     * "Information", "Warning", or "Error".     * @return string Message severity     */    public function getSeverity()    {        return $this->severity;    }

/**     * Sets the severity of the message     * @param $severity     * @return void     */    public function setSeverity($severity)    {        $this->severity = $severity;    }

public function getMessage()    {        return $this->message;    }

public function setMessage($msg)    {        $this->message = $msg;    }}

/* * Counts the messages with the given severity in the array * of messages. *  * @param $messages An array of ResultMessage * @return int Count of messages with a severity of "Error" */function countErrors($messages){    $matchingCount = 0;    foreach($messages as $m) {        if ($m->getSeverity() == "Error") {            $matchingCount++;        }    }    return $matchingCount;}

$messages = array(new ResultMessage("Error", "This is an error!"),    new ResultMessage("Warning", "This is a warning!"),    new ResultMessage("Error", "This is another error!"));

$errs = countErrors($messages);

echo("There are " . $errs . " errors in the result.\n");

?>

<?

// Get the actual name of the function convertDayOfWeekToName($day){    $dayNames = array(    "Sunday",    "Monday",    "Tuesday",    "Wednesday",    "Thursday",    "Friday",    "Saturday");    return $dayNames[$day];}

echo("The name of the 0 day is:  " . convertDayOfWeekToName(0) . "\n");echo("The name of the 10 day is:  " . convertDayOfWeekToName(10) . "\n");echo("The name of the 'orange' day is:  " . convertDayOfWeekToName('orange') . "\n");

?>

<?

/** * This is the exception thrown if the day of the week is invalid. * @author nagood * */class InvalidDayOfWeekException extends Exception { }

class InvalidDayFormatException extends Exception { }

/** * Gets the name of the day given the day in the week. Will * return an error if the value supplied is out of range. *  * @param $day * @return unknown_type */function convertDayOfWeekToName($day){    if (! is_numeric($day)) {        throw new InvalidDayFormatException('The value \'' . $day . '\' is an ' .            'invalid format for a day of week.');    }

if (($day > 6)  ($day < 0)) {        throw new InvalidDayOfWeekException('The day number \'' . $day . '\' is an ' .            'invalid day of the week. Expecting 0-6.');    }

$dayNames = array(    "Sunday",    "Monday",    "Tuesday",    "Wednesday",    "Thursday",    "Friday",    "Saturday");    return $dayNames[$day];}

echo("The name of the 0 day is:  " . convertDayOfWeekToName(0) . "\n");

try {    echo("The name of the 10 day is:  " . convertDayOfWeekToName(10) . "\n");} catch (InvalidDayOfWeekException $e) {    echo ("Encountered error while trying to convert value:  " . $e->getMessage() . "\n");}

try {    echo("The name of the 'orange' day is:  " . convertDayOfWeekToName('orange') . "\n");} catch (InvalidDayFormatException $e) {    echo ("Encountered error while trying to convert value:  " . $e->getMessage() . "\n");}

?>

<?/** * Counts the number of messages found in the array of  * ResultMessage with the getSeverity() value of "Error" *  * @param $messages An array of ResultMessage * @return unknown_type */function countErrors($messages){    $matchingCount = 0;    foreach($messages as $m) {        if ($m->getSeverity() == "Error") {            $matchingCount++;        }    }    return $matchingCount;}

/** * Counts the number of messages found in the array of  * ResultMessage with the getSeverity() value of "Warning" *  * @param $messages An array of ResultMessage * @return unknown_type */function countWarnings($messages){    $matchingCount = 0;    foreach($messages as $m) {        if ($m->getSeverity() == "Warning") {            $matchingCount++;        }    }    return $matchingCount;}

/** * Counts the number of messages found in the array of  * ResultMessage with the getSeverity() value of "Information" *  * @param $messages An array of ResultMessage * @return unknown_type */function countInformation($messages){    $matchingCount = 0;    foreach($messages as $m) {        if ($m->getSeverity() == "Information") {            $matchingCount++;        }    }    return $matchingCount;}

$messages = array(new ResultMessage("Error", "This is an error!"),    new ResultMessage("Warning", "This is a warning!"),    new ResultMessage("Error", "This is another error!"));

$errs = countErrors($messages);

echo("There are " . $errs . " errors in the result.\n");?>

<?    /*     * Counts the messages with the given severity in the array     * of messages.     *      * @param $messages An array of ResultMessage     * @return int Count of messages matching $withSeverity     */    function countMessages($messages, $withSeverity)    {        $matchingCount = 0;        foreach($messages as $m) {            if ($m->getSeverity() == $withSeverity) {                $matchingCount++;            }        }        return $matchingCount;    }

/**     * Counts the number of messages found in the array of      * ResultMessage with the getSeverity() value of "Error"     *      * @param $messages An array of ResultMessage     * @return unknown_type     */    function countErrors($messages)    {        return countMessages($messages, "Errors");    }

/**     * Counts the number of messages found in the array of      * ResultMessage with the getSeverity() value of "Warning"     *      * @param $messages An array of ResultMessage     * @return unknown_type     */    function countWarnings($messages)    {        return countMessages($messages, "Warning");    }

/**     * Counts the number of messages found in the array of      * ResultMessage with the getSeverity() value of "Warning"     *      * @param $messages An array of ResultMessage     * @return unknown_type     */    function countInformation($messages)    {        return countMessages($messages, "Information");    }

$messages = array(new ResultMessage("Error", "This is an error!"),        new ResultMessage("Warning", "This is a warning!"),        new ResultMessage("Error", "This is another error!"));

$errs = countErrors($messages);

echo("There are " . $errs . " errors in the result.\n");

?>