Question

Am having some trouble with a simple callback; am getting an ‘expected method body’ error even though I can’t find anything wrong. Have commented the error messages.

Logger.h

#import <Foundation/Foundation.h>

@interface Logger : NSObject

- (void)sayOuch:NSTimer *)t; // Expected ';' after method prototype

@end

Logger.m

#import "Logger.h"

@implementation Logger

- (void)sayOuch:NSTimer *)t // expected method body
{
    NSLog(@"Ouch!");
}

@end

main.m

#import <Foundation/Foundation.h>
#import "Logger.h"

int main (int argc, const char * argv[])
{

    @autoreleasepool {

       Logger *logger = [[Logger alloc]init];

       NSTimer *timer = [NSTimer scheduledTimerWithTimeInterval:2.0 
                                                      target:logger 
                                                    selector:@selector(sayOuch:) 
                                                    userInfo:nil 
                                                     repeats:YES]; 

        [[NSRunLoop currentRunLoop]run]; 

    }
    return 0;
}

Answer 1

You have

- (void)sayOuch:NSTimer *)t;

But you should have

- (void)sayOuch:(NSTimer *)t;

You missed the opening parenthesis for NSTimer *