Does 'this->' mean anything?

[jerry2037]

I'm teaching myself php & mysql. I understand most of what I read and see in downloaded scripts but this has me stumped:

Here is part of sample code from hotscripts
I understand this

var $HOST = "localhost";
var $USERNAME = "root";
var $PASSWORD = "";
var $DBNAME = "test";

Here is more code from the same script
I don't understand this

$connection = mysql_connect($this->HOST, $this->USERNAME, $this->PASSWORD);

What does the 'this->' do to the variable name when it is used in the mysql_connect function?

jerry

[MrAlaska]

Picking scripts apart can be fun, but if your intent is to learn PHP you shoud familiarize yourself at the source:
http://www.php.net/manual/en/

In this case, that syntax might have looked familiar from this-> page:
http://www.php.net/manual/en/language.oop.php

[Frag]

$this->var is for use within classes. (if you don't know what class objects are you should read up on OOP (Object Oriented Programming) Basicly you can create your own data type and create many copies of it with different data in it. You can also create member function that operate on that data. (functions that belong to the data object) When you have many copies of that data then $this->var tells php that you are talking about this exact object. That probably doesn't make since, but if you read up on OOP you will have a better understanding. When dealing with data in an object member function you need to use $this->var to access it.

I hope this helped more than confused 😉

Frag

[jerry2037]

Thanks MrAlaska,
I have to admit that when I was reading the WROX book "Beginning PHP4" I skipped over chapter 9 on objects, figuring that was just needed in VB and other oops.
Guess I'll go back and read it.
Then the comments posted on the link you sent me will probably be more meaningful too.
Jerry

[Bunkermaster]

Originally posted by jerry2037
I have to admit that when I was reading the WROX book "Beginning PHP4" I skipped over chapter 9 on objects

Do'h! read it now it allows a lot of nice things even if seldom used so far...