Using blocks to pass data back to view controller

Question

I was looking at this question.

One of the answers shows how to use blocks to pass data backwards view the prepareForSegue method. My understanding is t

Answer 1

sent data backward

1. declare block in your secondViewController.h file

   @property (nonatomic, copy)void(^myBlock)(NSString *);

2. call block wherever you need to pass data from .m file of secondViewController

   myBlock(@"this will displayed in firstViewController");

3.import above .h file in your firstViewController .m file and define your block as

secondViewController *ref =[[secondViewController alloc ]init];
  
     ref.myBlock =^void(NSString *data)
    {
    self.labelOffirstviewcontroller=data;
    };