Best way to define private variables in Objective-C

Question

I want to define private instance variables in MyClass.m file. It seems to me there are two ways to do it:

1. use class extension

   @interface HelloViewController () {      int value; } 

2. define in @implementation section

   @implementation HelloViewController {     int value; } 

Which is better?

I think recent Apple's coding style is to use class extension?

e.g. MasterViewController.m generated by 'Master-Detail Application Template'

@interface MasterViewController () {     NSMutableArray *_objects; } @end 

Answer 1

The "Modern Objective-C" way to do this is to declare them in your implementation block, like this:

@implementation ClassName {     int privateInteger;     MyObject *privateObject; }  // method implementations etc...  @end 

See this earlier post of me with more details.