Question about static properties in implementation (.m) file

Question

I've been using some static properties in my implementation files so they can be accessed by class methods like so for example:
#import etc
static Class foo; // <-- Here is where I've been defining static properties
@implementation Bar
- init {
foo = [Class new]; // initialize property
+ getObject { // now any where else in my code I can use [Foo getObject]
return foo;
- dealloc {
[foo release];
I've been doing this so that in other classes, I can simply go like:
[Foo getObject]
Can someone give me some more details about what's going on here though? It's been working but I'm nervous because I don't know much about it.
ie. What kind of property is it? (nonatomic, retain)? Is this bad practice?
Thanks to anyone who can shed some light on this.

Answer 1

First off, it's not a property. It's a static variable. And the code you have isn't a good idea. Static variables should NOT be set via instance methods.
Think about the following code:
// In some other class
Bar x = [[Bar alloc] init];
Bar y = [[Bar alloc] init];
Think about what just happened. In the 'foo' class you have now created two 'foo' objects and the first one is now leaked.
The proper way to initialize static variables is with the 'initialize' class method. This is only ever called once, the first time the class is referenced.
static Class foo;
@implementation Bar
+ (void)initialize {
foo = [[Bar alloc] init];
- init {
// Do nothing with 'foo'
+ (Bar)getObject {
return foo;
- (void)dealloc {
// Do nothing with 'foo'
The only downside, sort of, is that 'foo' is never dealloc'ed except when the app exits. But this isn't typically a problem.