Weak and strong property setter attributes in Objective-C

Question

What is the difference between weak and strong property setter attributes in Objective-C?

@property(retain, [weak/strong]) __attribute__((NSObject)) CFDictio         


        

Answer 1

let take an example to elaborate more(above answer are already great), may this example helps little more

let we have two class A and B

//A.h

#import 
#import "B.h"

@interface A : NSObject

@property (nonatomic, strong) B *objB;

@end

@implementation A
//

@end

//B.h

    #import 
    #import "A.h"


    @interface B : NSObject

    @property strong text(nonatomic, strong) A *objA;

    @end

    @implementation B
    //

    @end

    and in main

    #import "B.h"
    #import "A.h"

    {
    A *obja =[[A alloc]init];
    B *objb =[[B alloc]init];
    A.objB=objb;
    B.objA=obja;
   }

the above code will generate a retain cycle because both are the strong type a-------->b--------->a

so to avoid it you have to use week property of one of it so that it weekly refer to the object and not increase it reference count.