PHPDebug - http://www.codeforest.net/debugging-php-in-browsers-javascript-console

PHPDebug

class PHPDebug {
     
function __construct() {
    if (!defined("LOG"))    define("LOG",1);
    if (!defined("INFO"))   define("INFO",2);
    if (!defined("WARN"))   define("WARN",3);
    if (!defined("ERROR"))  define("ERROR",4);
 
    define("NL","\r\n");
    echo '<script type="text/javascript">'.NL;
     
    /// this is for IE and other browsers w/o console
    echo 'if (!window.console) console = {};';
    echo 'console.log = console.log || function(){};';
    echo 'console.warn = console.warn || function(){};';
    echo 'console.error = console.error || function(){};';
    echo 'console.info = console.info || function(){};';
    echo 'console.debug = console.debug || function(){};';
    echo '</script>';
    /// end of IE    
}
 
function debug($name, $var = null, $type = LOG) {
    echo '<script type="text/javascript">'.NL;
    switch($type) {
        case LOG:
            echo 'console.log("'.$name.'");'.NL;    
        break;
        case INFO:
            echo 'console.info("'.$name.'");'.NL;    
        break;
        case WARN:
            echo 'console.warn("'.$name.'");'.NL;    
        break;
        case ERROR:
            echo 'console.error("'.$name.'");'.NL;    
        break;
    }
     
    if (!empty($var)) {
        if (is_object($var) || is_array($var)) {
            $object = json_encode($var);
            echo 'var object'.preg_replace('~[^A-Z|0-9]~i',"_",$name).' = \''.str_replace("'","\'",$object).'\';'.NL;
            echo 'var val'.preg_replace('~[^A-Z|0-9]~i',"_",$name).' = eval("(" + object'.preg_replace('~[^A-Z|0-9]~i',"_",$name).' + ")" );'.NL;
            switch($type) {
                case LOG:
                    echo 'console.debug(val'.preg_replace('~[^A-Z|0-9]~i',"_",$name).');'.NL;    
                break;
                case INFO:
                    echo 'console.info(val'.preg_replace('~[^A-Z|0-9]~i',"_",$name).');'.NL;
                break;
                case WARN:
                    echo 'console.warn(val'.preg_replace('~[^A-Z|0-9]~i',"_",$name).');'.NL;        
                break;
                case ERROR:
                    echo 'console.error(val'.preg_replace('~[^A-Z|0-9]~i',"_",$name).');'.NL;    
                break;
            }
        } else {
            switch($type) {
                case LOG:
                    echo 'console.debug("'.str_replace('"','\\"',$var).'");'.NL;
                break;
                case INFO:
                    echo 'console.info("'.str_replace('"','\\"',$var).'");'.NL;
                break;
                case WARN:
                    echo 'console.warn("'.str_replace('"','\\"',$var).'");'.NL;    
                break;
                case ERROR:
                    echo 'console.error("'.str_replace('"','\\"',$var).'");'.NL;
                break;
            }
        }
    }
    echo '</script>'.NL;
}
}

PHPDebug2

// include and instantiate the class
    require_once("PHPDebug.php");
    $debug = new PHPDebug();
     
    // simple message to console
    $debug->debug("A very simple message");
     
    // vaiable to console
    $x = 3;
    $y = 5;
    $z = $x/$y;
    $debug->debug("Variable Z: ", $z);
     
    // a warnign
    $debug->debug("A simple Warning", null, WARN);
     
    // info
    $debug->debug("A simple Info message", null, INFO);
     
    // An error
    $debug->debug("A simple error messsage", null, ERROR);
     
    // Array in console
    $fruits = array("banana", "apple", "strawberry", "pineaple");
    $fruits = array_reverse($fruits);
    $debug->debug("Fruits array", $fruits);
     
     
    // object to console
    $book               = new stdClass;
    $book->title        = "Harry Potter and the Prisoner of Azkaban";
    $book->author       = "J. K. Rowling";
    $book->publisher    = "Arthur A. Levine Books";
    $book->amazon_link  = "http://www.amazon.com/dp/0439136369/";
    $debug->debug("Object", $book);