ivar example

// in the .h file

@interface Foo : Bar {
@public
  int _ivar1;
@protected
  int _ivar2;
  int _property2;
@private
  int _ivar3;
}

// This will automatically declare a private "int _property1" ivar. (unless you implement both the getter and setter)
@property int property1;

// This property will use the use the _property2 ivar you declared above.
@property int property2;

@end

// in the .m file

@implementation Foo {
  // You can put ivars in here too.
  // They _can_ be public/protected, but there isn't much point unless you declare them in the header.
  int _ivar4;
}

@end