NSDictionary Objective-C

Question

I\'m trying to store data in the following fashion with a string as the key and I would like an array as the value.

key objects

\"letters\"

Answer 1

A simple way to do this in code (and just one of many several ways you could do it):

NSMutableDictionary *dict = [NSMutableDictionary dictionary];
[dict setObject:[NSArray arrayWithObjects:@"a", @"b", @"c", @"d", nil] forKey:@"letters"];
[dict setObject:[NSArray arrayWithObjects:[NSNumber numberWithInt:1], [NSNumber numberWithInt:2], [NSNumber numberWithInt:3], [NSNumber numberWithInt:4], nil] forKey:@"numbers"];

That creates an NSDictionary with an array of strings and an array of NSNumber objects, there are other ways to create arrays, but that demonstrates a basic way to do it.

Per the comments below:

If you wanted to add items to the arrays one at a time...

  // create the dictionary and add the letters and numbers mutable arrays
  NSMutableDictionary *dict = [NSMutableDictionary dictionary];
  NSMutableArray *letters = [NSMutableArray array];
  NSMutableArray *numbers = [NSMutableArray array];
  [dict setObject:letters forKey:@"letters"];
  [dict setObject:numbers forKey:@"numbers"];

  // add a letter and add a number
  [[dict objectForKey:@"letters"] addObject:@"a"];
  [[dict objectForKey:@"numbers"] addObject:[NSNumber numberWithInt:1]];  
  // This now has an NSDictionary (hash) with two arrays, one of letters and one 
  // of numbers with the letter 'a' in the letters array and the number 1 in 
  // the numbers array