//-----demonstrate how blocks hold their captured state
NSDate *date = [NSDate date];
void (^now)(void) = ^ {
    NSLog(@"The date and time is %@", date);
};
now();
sleep(5);
date = [NSDate date];
now();


//--------------
    int (^triple)(int) = ^(int number) {
        return number * 3;
    };
    int result1 = triple(2);
    
    int (^multiply)(int, int) = ^(int x, int y) {
        return x * y;
    };
    int result2 = multiply(2, 3);
    NSLog(@"result %i", result2);
    result2 = multiply(5, 3);
    NSLog(@"result %i", result2);

Examples of how Objective-c objects work

xcode Objective C - block examples

Objective C