Error When Calling Function - php

Question

I searched forever trying to find an answer, but was ultimately stumped. I've been writing code to allow multiple bots to connect to a chat box. I wrote all the main code and checked it over to make sure it was all okay. Then when I got to calling the function needed to make it work, it gave me an error saying:
Notice: Undefined variable: ip in C:\wamp\www\BotRaid.php on line 40
And also an error saying:
Fatal Error: Cannot access empty property in C:\wamp\www\BotRaid.php
on line 40
( Also a screenshot here: http://prntscr.com/ckz55 )
<?php
date_default_timezone_set("UCT");
declare(ticks=1);
set_time_limit(0);
class BotRaid
{
public $ip="174.36.242.26";
public $port=10038;
public $soc = null;
public $packet = array();
##############################
# You can edit below this #
##############################
public $roomid="155470742";
public $userid = "606657406";
public $k = "2485599605";
public $name="";
public $avatar=;
public $homepage="";
##############################
# Stop editing #
##############################
public function retry()
{
$this->connect($this->$ip,$this->$port); //Line 40, where I'm getting the error now.
$this->join($this->$roomid);
while($this->read()!="DIED");
}
public function connect($ip, $port)
{
if($this->$soc!=null) socket_close($this->$soc);
$soc = socket_create(AF_INET,SOCK_STREAM,SOL_TCP);
if(!$this->$soc)$this->port();
if(!socket_connect($this->$soc,$this->$ip,$this->$port))$this->port();
}
public function port()
{
$this->$port++;
if($this->$port>10038) $this->$port=10038;
$this->retry();
}
public function join($roomid)
{
$this->send('<y m="1" />');
$this->read();
$this->send('<j2 q="1" y="'.$this->$packet['y']['i'].'" k="'.$this->$k.'" k3="0" z="12" p="0" c"'.$roomid.'" f="0" u="'.$this->$userid.'" d0="0" n="'.$this->$name.'" a="'.$this->$avatar.'" h="'.$this->$homepage.'" v="0" />');
$this->port();
$this->$roomid;
}
public function send($msg)
{
echo "\n Successfully connected.";
socket_write($this->$soc, $this->$msg."\0", strlen($this->$msg)+1);
}
public function read($parse=true)
{
$res = rtrim(socket_read($this->$soc, 4096));
echo "\nSuccessfully connected.";
if(strpos(strtolower($res), "Failed"))$this->port();
if(!$res) return "DIED";
$this->lastPacket = $res;
if($res{strlen($res)-1}!='>') {$res.=$this->read(false);}
if($parse)$this->parse($res);
return $res;
}
public function parse($packer)
{
$packet=str_replace('+','#più#',str_replace(' ="',' #=#"',$packet));
if(substr_count($packet,'>')>1) $packet = explode('/>',$packet);
foreach((Array)$packet as $p) {
$p = trim($p);
if(strlen($p)<5) return;
$type = trim(strtolower(substr($p,1,strpos($p.' ',' '))));
$p = trim(str_replace("<$type",'',str_replace('/>','',$p)));
parse_str(str_replace('"','',str_replace('" ','&',str_replace('="','=',str_replace('&','__38',$p)))),$this->packet[$type]);
foreach($this->packet[$type] as $k=>$v) {
$this->packet[$type][$k] = str_replace('#più#','+',str_replace('#=#','=',str_replace('__38','&',$v)));
}
}
}
}
$bot = new BotRaid; //This is where I had the error originally
$bot->retry();
?>
Line 40 is below the "Stop Editing" line. Anyone have any suggestions? Or perhaps need me to clear some things up?

Answer 1

You are accessing the properties of the class incorrectly.
The line:
$this->connect($this->$ip,$this->$port);
Should be:
$this->connect($this->ip, $this->port);
Since there was no local variable called $ip, your expression was evaluating to $this-> when trying to access the property since PHP lets you access properties and functions using variables.
For example, this would work:
$ip = 'ip';
$theIp = $this->$ip; // evaluates to $this->ip
// or a function call
$method = 'someFunction';
$value = $this->$method(); // evaluates to $this->someFunction();
You will have to change all the occurrences of $this->$foo with $this->foo since you used that notation throughout the class.
As noted in the comment by #Aatch, see the docs on variable variables for further explanation. But that is what you were running into accidentally.