Only the last value of NSMutableDictionary is added to NSMutableArray

Question

I have tried my best to search for the answers to add NSMutableDictionary to NSMutableArray. Unfortunately, they all asked me to use "[allValues]" which is not what I want.

Here is the issue,

In the header file, I defined,

NSMutableArray *arData;

And in the m file,

arData = [[NSMutableArray alloc] init];

NSMutableDictionary *mutableDictionary5 = [[NSMutableDictionary alloc]init];

for (i=0;i<[[[self rssParser]rssItems]count];i++)
{

    Lat = [[[[[self rssParser]rssItems]objectAtIndex:i]lat] doubleValue];
    Lng = [[[[[self rssParser]rssItems]objectAtIndex:i]lng] doubleValue];
    // Creates a marker in the center of the map.
    GMSMarker *marker = [[GMSMarker alloc] init];
    marker.position = CLLocationCoordinate2DMake(Lat, Lng);
    marker.title = [[[[self rssParser]rssItems]objectAtIndex:i]header];

[mutableDictionary5 setObject:marker.title forKey:@"title"];

[arData setValue:[mutableDictionary5 valueForKey:@"title"] forKey:@"title"];
}

The "arData" only gets the last value of [[[[self rssParser]rssItems]objectAtIndex:i]header].And I am sure mutableDictionary5 gets all the value since I have put the following at the end of the code,

 NSLog(@"mutableDictionary5 values=%@",[mutableDictionary5 allValues]);

It prints all the value of the title.

I understand it shouldn't be setvalue, however, I tried to use [mutableDictionary5 allValues], "addobjects", "allkeys". They are not working. What should I do to let the NSMutableArray arData to add all values of title with "title" as the key? thanks.

Sorry for my bad English which is not my native language.

Answer 1

You erroneously use setValue instead of addObject.

[arData addObject:mutableDictionary5]; 

This will work if you alloc init a new dictionary inside the loop.
If you want to reduce the array to just titles do this after the loop:

NSArray *titleArray = [arData valueForKeyPath:@"title"]; 

Now you have an array containing just titles.

BTW, you could make some effort to invent better variable names. Note that by convention in Objective-C variable names start with low cap while class names are capitalized.