How to store an NSArray in an NSDictionary?

问题

I'm trying to teach myself but am struggling with how to store something like an NSArray inside an NSDictionary.

Let's say hypothetically you had a NSDictionary for recipes:

Let's say the NSDictionary had keys like:

Spaghetti, Fettucine Alfredo, Grilled Chicken Salad

And the NSDictionary had an NSArray which was simply a list of ingredients.

I suppose the equivalent PHP code would be something like:

$['Spaghetti'] = array('Spaghetti Pasta', 'Spaghetti Sauce', 'Meatballs');
$['Fettucine Alfredo'] = array('Fettucine Pasta', 'Alfredo Sauce');
$['Grilled Chicken Salad'] = array('Lettuce', 'Grilled Chicken', 'Croutons');

I'm struggling with how I can add an NSArray to the NSDictionary. Then what if I wanted to remove an element or add an element to the array? How is it retrieved and deleted or added to?

回答1:

NSDictionary* dict = [NSDictionary dictionaryWithObjectsAndKeys:
  [NSArray arrayWithObjects:@"Spaghetti Pasta", @"Tomato Sauce", nil], @"Spaghetti",
  [NSArray arrayWithObjects:@"Fettuccine Pasta", @"Alfredo Sauce", nil], @"Fettuccine Alfredo",
  [NSArray arrayWithObjects:@"Lettuce", @"Grilled Chicken", @"Croutons", nil], @"Grilled Chicken Salad",
  nil];

You can add any object type to a dictionary as a value. For more on dictionaries, see the documentation.

来源：https://stackoverflow.com/questions/3155328/how-to-store-an-nsarray-in-an-nsdictionary