Instance variable 'variable' accessed in class method error

If you meant to make this an instance method, change that + to -.

1. For + (void)hit:Only have access to the self object.

--Step 1: Remove follwing line from header file

@property (nonatomic, readwrite) int _nPerfectSlides;

--Step 2:

• Add int _nPerfectSlides in your class file globally..
• That means declare before @implementation

Eg: In .m File

#import "Controller.h"
int _nPerfectSlides // Add like this before @implementation

@implementation Controller

---

2. For - (void)hit:Only have access to the instance methods

An instance variable is, as its name suggests, only accessible in the instance methods (those declared with -). Class methods (declared with +) have no access to instance variable, no more than they have access to the self object.