Question

I am new to Xcode and Objective-C programming and need some help.

I am looking to create a basic program for the iOS that uses hierarchal-data and 2 separate UITableViews. I want the second UITableView to be populated by an array that is passed between viewControllers, based on which cell/row is selected in the first UITableView.

The program compiles but I get a SIGABRT error when running the program. Can someone help me fix the SIGABRT and pass the mainArray to the second tableView?

Here is how far I have gotten.

My code:

ArrayTableViewController.h

@interface arrayTableViewController : UITableViewController
@property (nonatomic, strong) NSMutableArray *mainArray;
@property (nonatomic, strong) NSMutableArray *secondArray;
@property (nonatomic, strong) NSMutableArray *thirdArray;
@end

ArrayTableViewController.m

#import "ArrayTableViewController.h"
#import "table2.h"
@implementation arrayTableViewController
@synthesize mainArray, secondArray, thirdArray;

-(void) viewDidLoad {
[super viewDidLoad];
mainArray = [[NSMutableArray alloc] initWithObjects: secondArray,     thirdArray, nil];
secondArray = [[NSMutableArray alloc] initWithObjects: @"123", @"456",     nil];
thirdArray = [[NSMutableArray alloc] initWithObjects: @"78", @"90", nil];
}



- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
return [mainArray count];
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = @"Cell";

UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
    cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
}


cell.textLabel.text = [mainArray objectAtIndex:[indexPath row]];

return cell;
}

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{

table2 *table2Controller = [[table2 alloc] initWithNibName:@"table2" bundle:nil];
table2Controller.arrayForDisplay = [[mainArray objectAtIndex: [indexPath row]] objectAtIndex:1];
[self.navigationController pushViewController:table2Controller animated:YES];

}

@end

table2.h

#import <UIKit/UIKit.h>
@interface table2 : UITableViewController
@property (nonatomic, strong) NSArray *arrayForDisplay;
@end

table2.m

@implementation table3
@synthesize arrayForDisplay;

Then the same cell configuration style that was used in ArrayTableViewController.m

Edits:

After making the necessary changes, when I run the program and select a row, I get a SIGABRT error at the following line.

int main(int argc, char *argv[])
{
@autoreleasepool {
    return UIApplicationMain(argc, argv, nil, NSStringFromClass([ArrayTableAppDelegate class]));
}
}

What would you recommend? Should I turn off ARC and call my own releases? so that I can get to the second tableView?

Answer 1

First mistake:

In viewDidLoad method, you have created the mainArray with secondArray and thirdArray as elements even before you allocated those arrays.

Second mistake:

In cellForRowAtIndexPath: method:

Check the line cell.textLabel.text = [mainArray objectAtIndex:[indexPath row]];

Actually the textLabel expects a NSString value to set. But you are setting an array.

Edit:

Set the value to textLabel as following:

cell.textLabel.text = [[mainArray objectAtIndex:[indexPath row]] objectAtIndex:0];

Actually this will set the first value of the array. But that it depends on your requirement.

Edit 2:

arrayForDisplay is an array variable but you are setting a string variable to that in the statement

table2Controller.arrayForDisplay = [[mainArray objectAtIndex: [indexPath row]] objectAtIndex:1];

Do it as follows:

table2Controller.arrayForDisplay = [mainArray objectAtIndex: [indexPath row]];