objective-c - Change Table Data in Function

Question

I have a program that changes the data of a table (among other things). In a function (specifically when triggered by a button), I have the code below, but it says, "use of undeclared identifier 'tableView' ". However, outside of this, I have this run when I start the program, and it works.

- (id)tableView:(NSTableView *)aTableView objectValueForTableColumn:(NSTableColumn *)aTableColumn row:(NSInteger)rowIndex {
    if ([aTableColumn.identifier isEqualToString:@"row1"]){
        return everything2[rowIndex];
    }
    return everything[rowIndex];
}

I was watching a tutorial and I don't remember everything I did, so do I have to declare, delegate, link the function, or something else?

This is the declaration of everything(2):

NSString *everything[115];
NSString *everything2[115];