[RESOLVED] A few class questions

RonB

When reading a few php class tutorials, I noticed every now and then "public" prefixed before "function", but what does that mean? Are those functions (that are stated as public) available to anyone using the class? If so, should I prefix all my functions as public?

Is there a way to make a function private in a class so only the class functions can call it?

I read in other tutorials about initiating your variables like this.

class test
{
  var $var1;
  var $var2;
  var $var3;
}

But why can't you just initiate the variables you normally would when using PHP. Like this.

$test = "testing...";

NogDog

Private variables and/or functions in a class can only be accessed by methods (functions) within that class. You cannot directly call them from outside of the class. This is a major part of the implementation of the object-oriented concept of encapsulation and data-hiding: only allowing external code to directly access those parts of a class that it needs to, while hiding the rest of the class's internal implementation.

PS: Note that this private/public aspect of classes is only available in PHP5; in PHP4 all methods and class variables are public.

RonB

I'm sorry, I understand what you're saying, but my questions were left unanswered. How do I make functions, which are inside a class, as private functions? Do I just use the prefix "private"? And why do I have to initiate variables in a class, can't I just use them normally by just doing this: $text = 'text';

Thank you

NogDog

You do not "have" to initialize class variables. It is, however, generally a good practice to do so to ensure that all variables start in a known state. Class variables and methods may be defined as public, private, or protected as explained in this manual page (with several of examples).