Hi all,
a quick question about using PHP's objects, specifically in terms of the
scope of class attributes:
Normally, in PHP, a variable in a function is local to that function and
is NOT a reference to a similarly-named variable outside the function,
right? To the best of my knowledge, there are several ways to allow
access to an outside variable from within a function:
1) Declare the variable as global with the "global" keyword
2) Access it from the $GLOBALS array
3) Pass the variable to the function as a parameter
and probably others, but it's really beside the point because I don't
have a question about normal functions. What I am really wondering is
if there is any formal "rules" about the scope of Class Attributes in
Class definitions and in methods -- they do not behave identical to
PHP's functions. For instance, I can access a class attribute from
within a method of that class without explicitly declaring that
attribute global inside the method, or without explicitly passing that
attribute as a parameter to the method. So they seem to behave as if
they are always global.
But if I want to make a change to that class attribute from within a
method, am I affecting a copy of the class attribute, or the class
attribute itself? The reason I ask is because I have a Class that is
behaving oddly. Here is the relevant part of the code:
Class Folder
{
// declare class attributes
var $contents = array();
// a method to add to $contents
function add_to_contents($item)
{
$this->contents[] = $item;
}
// a method to remove from $contents
function rm_item($index)
{
unset($this->contents[$index]);
}
}
The crux of my question is, does this have the effect that it appears to
have? I am hoping someone with thorough understanding of the internals
of PHP can give me a definitive answer. My tests are coming up with
strange results, so I haven't figured it out on my own yet.
Thanks in advance,
Erik
PS: FYI, if you unset an array element, there is still an index for that
element -- the array does not reindex itself. A good solution to this,
that a fellow lister named Nathan gave me, is to array_push() a dummy
var onto the end of the array and then array_pop() it back off -- this
reindexes the array. But I am finding that somehow my arrays are
"remembering" old elements that I could have sworn I unset, so I am
asking the above question about the scope of class attributes in methods.
----
Erik Price
Web Developer Temp
Media Lab, H.H. Brown
[EMAIL PROTECTED]
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