Adding to a Previously saved NSUserDefaults - ios

Question

I am making a game for iOS which in includes a scoring system in each level. Here I have some code that gets an NSString (passedValue1) by using a delegate.
Heres the code for the delegate:
LevelCompleteLevel1
.h
#import "ViewController.h"
#interface LevelCompleteLevel1 : UIViewController{
IBOutlet UILabel *label;
ViewController *secondviewData;
}
#property (nonatomic, retain)ViewController*secondviewData;
.m
ViewController *second = [[ViewController alloc] initWithNibName:nil bundle:nil];
self.secondviewData = second;
secondviewData.passedValue1 = label.text;
[self presentModalViewController:second animated:YES];
In the .m I send the a value from a label in the current viewcontroller to another view controller the value I send is called passedValue1
Once I have sent the value I need to display and save in my ViewController
ViewController
.h
#interface ViewController : UIViewController{
IBOutlet UILabel *label;
NSString *passedValue1;
}
#property (nonatomic, retain)NSString *passedValue1;
#end
.m
Firstly I ... #synthesize passedValue1;
Then i add the code to receive the value in my viewDidLoad and display my value in a UILabel
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib
NSString *key=#"labelKey";
// Do any additional setup after loading the view, typically from a nib
if(passedValue1){
NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
NSObject * object = [prefs objectForKey:key];
if(object != nil){
NSUserDefaults *defults = [NSUserDefaults standardUserDefaults];
[defults setObject:passedValue1 forKey:key];
[defults synchronize];
}
else{
NSUserDefaults *defults = [NSUserDefaults standardUserDefaults];
NSInteger readScore=[[[NSUserDefaults standardUserDefaults] objectForKey:key] integerValue];
NSInteger newValue=readScore+[passedValue1 integerValue];
[defults setObject:[NSString stringWithFormat:#"%d",newValue] forKey:key];
[defults synchronize];
}
}
label.text = [[NSUserDefaults standardUserDefaults]objectForKey:key];
}
Once I have displayed the value I then save it into a label using a NSUserDefault. However, once I have replayed my game and have another score value I would like to add the new passedValue1 value to the currently saved value...
For example:
say I play my level and I get the score value of 10. The value is then saved and I replay my level. I would then like to take the saved value and add it to the value i just scored. So thats say the second value I have scored is 20. I would then like my code to add them together and give me a value of 30.
can anyone help because the code I'm using does not correctly do the function that I want to do which is add the previous and the currently passed value.
Thanks in advance.
edit
Iam using this code:
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib
NSString *key=#"labelKey";
// Do any additional setup after loading the view, typically from a nib
if(passedValue1){
NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
NSObject * object = [prefs objectForKey:key];
if(object != nil){
NSUserDefaults *defults = [NSUserDefaults standardUserDefaults];
[defults setObject:passedValue1 forKey:key];
[defults synchronize];
}
else{
NSUserDefaults *defults = [NSUserDefaults standardUserDefaults];
NSInteger readScore=[[[NSUserDefaults standardUserDefaults] objectForKey:key] integerValue];
NSInteger newValue=readScore+[passedValue1 integerValue];
[defults setValue:[NSString stringWithFormat:#"%d",newValue] forKey:key];
[defults synchronize];
}
}
label.text = [[NSUserDefaults standardUserDefaults]objectForKey:key];
}
Why is this not working , the displayed value of the label is the originally passedValue1?

Answer 1

once try this one ,
NSUserDefaults *defaults=[NSUserDefaults standardUserDefaults];
[defaults setObject:#"10" forKey:#"old value"];
[defaults synchronize];
int k=[[defaults objectForKey:#"old value"] intValue]+newValue;

Answer 2

Two things
As you are adding the NSString it is enough to use the setValue: forKey: method. (NOT setObject:forKey as you are using)
NSUserDefaults is a key based value saving mechanism. If you try to save the value in the same key the saved value will be replaced by the current saving value.
So in your case just call for the same key with the new value and you have the older value replaced with new one.