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iOS Object-Oriented Objective-C Memory, Arrays and Loops, Oh My! Review Dictionaries and Arrays

Mia Pivirotto
Mia Pivirotto
5,557 Points
Posted by Mia Pivirotto
Mia Pivirotto
5,557 Points

How to add items from an array into a mutable dictionary?

From the beginning was:

  1. Create an NSArray called 'shoeOrder' and give the array the following four elements, in the following order: @"Charles Smith", @(9.5), @"loafer", @"brown". Be sure to use the literal syntax. NSArray *shoeOrder = @[@"Charles Smith", @(9.5), @"loafer", @"brown"];

  2. It looks like we actually want this information in a dictionary, rather than an array. Create an empty NSMutableDictionary called 'shoeOrderDict'. NSMutableDictionary *shoeOrderDict = [[NSMutableDictionary alloc] init];

  3. Now add the values in our array to our new dictionary. The keys for the values should be: 'customer', 'size', 'style' and 'color'. The values in the original array are in the same order as the keys listed above. (Note: Don't set the values directly as strings, but rather use something like 'objectAtIndex' to reference the original array.)

And I am stuck on the adding the values from my array into my new dictionary. What am I doing wrong?

variable_assignment.mm 
NSArray *shoeOrder = @[@"Charles Smith", @(9.5), @"loafer", @"brown"];

NSMutableDictionary *shoeOrderDict = [[NSMutableDictionary alloc] initwithObjectAtIndex: @[shoeOrder objectAtIndex: 0], @"customer", @[shoeOrder objectAtIndex: 1], @"size", @[shoeOrder objectAtIndex: 2], @"style", @[shoeOrder objectAtIndex: 3], @"color"];
wwyattw
wwyattw
10,389 Points

First, you need to keep the empty dictionary as it is, then set a value for each key. 

[shoeOrderDict setObject:[shoeOrder objectAtIndex:0] forKey:@"customer"];
[shoeOrderDict setObject:[shoeOrder objectAtIndex:1] forKey:@"size"];
[shoeOrderDict setObject:[shoeOrder objectAtIndex:2] forKey:@"style"];
[shoeOrderDict setObject:[shoeOrder objectAtIndex:3] forKey:@"color"];