I'm getting this error: -[NSCFArray insertObject:atIndex:]: attempt to insert nil

Here is the .m file:

/*
 IBOutlet NSTextField *textField;
 IBOutlet NSTabView *tableView;
 IBOutlet NSButton *button;
 NSMutableArray *myArray;
 */

#import "AppController.h"


@implementation AppController


-(IBAction)addNewItem:(id)sender
{
    myArray = [[NSMutableArray alloc]init];
    tableView = [[NSTableView alloc] init];
    [tableView setDataSource:self];
    [textField stringValue];
    NSString *string = [[NSString alloc] init];
    string = [textField stringValue];



    [myArray addObject:string];
    NSLog(@"%d",[myArray count]);
    NSLog(@"%@",string);

}

- (int)numberOfRowsInTableView:(NSTableView *)aTableView
{
    return [myArray count];
}
- (id)tableView:(NSTableView *)aTableView
objectValueForTableColumn:(NSTableColumn *)aTableColumn
            row:(int)rowIndex
{
    //NSString *data = [myArray objectAtIndex:rowIndex];
    return [myArray objectAtIndex:rowIndex];
}




@end