Question

I’m trying to place a function inside another function, but I’m getting:

‘self’ was not declared in this scope

This is the code:

-(void) alone {
    label.text = [NSString stringWithFormat:@"Hello world"];
}

void *multithreading( void *ptr ) {
    [self alone];
}

Well then O found out, that the warning/error goes away if the last code is changed to:

-(void *) multithreading:( void * )ptr {
    [self alone];
}

I’m trying to keep multithreading stay the same way or else my code won’t work, so please help me out.

Answer 1

You can not access objective-c variable in c function. you should pass self as parameter to c function .

void *multithreading( void *ptr , void *info) {// self in info
    id obj;
    if (info)
   {
    obj = (id)info;
    [obj alone];
   }
}