syntax question

[rakennedy75]

I bought a new book on php called "Secure PHP Developement"
I have to say this is a little more advanced than my current knowledge.
I am determined to figure this out. One of the reasons it seems to be more advanced is that it uses classes which I don't have to much experience in using, at least with php I don't. One part of the code the book doesn't seem to explain is a specific syntax that I have not come across yet. Here is an example script I found.

 [code=php] function connect()
  {
     // connect to the database
     $status = $this->dbh = DB::connect($this->db_url);

     if (DB::isError($status))
     {
         $this->connected = FALSE;
         $this->error = $status->getMessage();
     } else {
         $this->connected = TRUE;
     }
     return $this->connected;
  }[/code]

I know php uses the -> to replace the dot in language such as java. The part I don't know anything about is the :: syntax

I have not ran across this in any scripts or books in my time learning php
Any explanation on this syntax or a link to one would be of great help

Thanks for your time

[LordShryku]

Never seen it used beyond the pear libraries...

[swr]

It's for calling functions in a class, without requiring an instance. Also known as "static methods" or "class methods" (as opposed to "instance methods").

error_reporting(E_ALL);

class Foo {
    var $value;

// This is a static method.
// It doesn't require any instance variables.
function a() {
    echo "Foo!<br>";
}

// This is an instance method.
function b() {
    echo "$this->value<br>";
}

}

Foo::a();
Foo::b(); // Undefined variable: this

$foo = new Foo();
$foo->value = "Bar!";
$foo->a();
$foo->b();                          

[Weedpacket]

In this case (instance?) the DB class is just a toolkit of related functions and some defined constants. There's no DB object as such (note the absence of any "$foo = new DB" in the script).

More details on the manual page titled ::, which is inexplicably pronounced "paamayim-nekudotayim".

[drawmack]

hey weed I still can't pronounce it, I'll just call it joe