Property declaration:
@property(attributes) type name;Accessor method names
- getter=getterName Specifies the name of the getter method.
- setter=setterName Specifies the name of the setter method.
Writability
- readwrite Read and write property.
- readonly Property can be only red.
Setter semantics
- assign The setter is simple assignment. You typically use this setter with non-pointer variables like: NSInteger, float and CGRect.
- retain Specifies that retain will be called each time a new assignment is done. The previous value of the property will be released.
- copy A copy of the object will be used in the assignment. No retain is called, but a release is send to the previous object.
Atomicity
- nonatomic It’s used in multithreaded environments to avoid that two or more different thread access the same property at same time.