Question

My iphone app writes key-value pairs to a dictionary in a plist file. I’m basically saving the user’s score when they play the game. This is all fine and dandy, but each time I run the app and get new scores, the new values get saved over the old values. How do I add information to the plist each time the user accesses the app instead of rewriting the file? I want to keep all of the scores, not just the most recent one.

code:

-(void)recordValues:(id)sender {

    //read "propertyList.plist" from application bundle
    NSString *path = [[NSBundle mainBundle] bundlePath];
    NSString *finalPath = [path
                          stringByAppendingPathComponent:@"propertyList.plist"];
    dictionary = [NSMutableDictionary dictionaryWithContentsOfFile:finalPath];

    //create an NSNumber object containing the
    //float value userScore and add it as 'score' to the dictionary.
    NSNumber *number=[NSNumber numberWithFloat:userScore];
    [dictionary setObject:number forKey:@"score"];

    //dump the contents of the dictionary to the console 
    for (id key in dictionary) {
        NSLog(@"memory: key=%@, value=%@", key, [dictionary
                                                 objectForKey:key]);
    }

    //write xml representation of dictionary to a file
    [dictionary writeToFile:@"/Users/rthomas/Sites/propertyList.plist" atomically:NO];
}

Answer 1

You are setting the object to a number for key score

    NSNumber *number=[NSNumber numberWithFloat:userScore];   
 [dictionary setObject:number forKey:@"score"];

Instead of this what you want to do is have an array or something of the sort so

NSNumber *number=[NSNumber numberWithFloat:userScore];  
    NSMutableArray *array=[dictionary objectForKey:@"score"]
     [array addObject:number]
    [dictionary setObject:array forKey:@"score"]

this should do what you are asking