xCode 4.5 Navigation Controller and back button how to save values - xcode

Question

In my code I created this
#import <UIKit/UIKit.h>
#interface ViewControllerTable : UIViewController <UITableViewDelegate, UITableViewDataSource>
#property (weak, nonatomic) IBOutlet UITableView *myTableView;
#property (strong, nonatomic) NSString *plcVar;
#end
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
listaPlacas *placas = [[listaPlacas alloc]init];
[self.navigationController pushViewController:placas animated:YES];
}
But in the other view:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
for (UITableViewCell *cell in [tableView visibleCells]) {
cell.accessoryType = UITableViewCellAccessoryNone;
}
UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];
cell.accessoryType = UITableViewCellAccessoryCheckmark;
NSString *placaVar = cell.textLabel.text;
ViewControllerTable *VCT = [[ViewControllerTable alloc]init];
VCT.plcVar = [[NSString alloc]init];
VCT.plcVar = placaVar;
}
When I click in back button the value in variable plcVar is empty.

Answer 1

I assume that "other view" is the viewController you push to from your first ViewController, and you are trying to set a property in the firstViewController from your otherViewController.
Then here is where you go wrong:
ViewControllerTable *VCT = [[ViewControllerTable alloc]init];
You are creating a new instance of VCT, when in fact you want a reference to the VCT that you pushed from.
You can get this via your navigation controller...
NSArray* viewControllers = [self.navigationController viewControllers];
ViewControllerTable* VCT = [viewControllers objectAtIndex:
[ viewControllers count]-2];