OC：MZSafeCallBack

DetailViewController

// DetailViewController.h
#import <UIKit/UIKit.h>

@interface DetailViewController : UIViewController

@property (nonatomic, copy) void (^passValueBlock)(NSString *text, BOOL isTrue, NSString * _Nullable type);

@end


// DetailViewController.m
#import "DetailViewController.h"

#define MZSafeCallBack(aBlock, ...) do {!aBlock ?: aBlock(__VA_ARGS__);} while(0)

@interface DetailViewController ()

@end

@implementation DetailViewController

- (IBAction)onBackPage:(id)sender {
    
    MZSafeCallBack(self.passValueBlock, @"success", YES, nil);
    [self.navigationController popViewControllerAnimated:YES];
}

@end

HomeViewController

#import "HomeViewController.h"

#import "DetailViewController.h"

@interface HomeViewController ()

@end

@implementation HomeViewController

- (IBAction)onNextPage:(id)sender {
 
    DetailViewController *detailVC = [[DetailViewController alloc] init];
    detailVC.passValueBlock = ^(NSString * _Nonnull text, BOOL isTrue, NSString * _Nullable type) {
      NSLog(@"text = %@, isTrue = %d, type = %@", text, isTrue, type);
    };
    [self.navigationController pushViewController:detailVC animated:YES];
}

@end

拓展
null 打印出是尖括号<null>，nil 是圆括号(null)

NSLog(@"%@--%@", [NSNull null], nil);
打印出：<null>--(null)