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

Andre Robinson
PLUS
Andre Robinson
Courses Plus Student 6,057 Points

Please help

I don't know what I'm doing wrong

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

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

NSMutableDictionary * shoeOrder = [[NSMutableDictionary alloc] objectAtIndex : 'customer','size','style','color'];

2 Answers

Anjali Pasupathy
Anjali Pasupathy
28,883 Points

You're nearly there. Your last line is a bit buggy, though.

You want to use two methods: the setValue:forKey: method on shoeOrderDict, and the objectAtIndex: method on shoeOrder.

The setValue:forKey: method has the following syntax:

[shoeOrderDict setValue: /* INSERT VALUE HERE */ forKey: /* INSERT KEY HERE */];

This method can only take one key-value pair at a time, so you'll have to use it 4 times in your code.

The keys are the NSString literals given in the challenge: @"customer", @"size", @"style", and @"color". The values are the contents of the array. While you could access each member of the array with subscript syntax (i.e. shoeOrder[0], etc.), this challenge wants you to use the objectAtIndex: method on shoeOrder to access the elements in the array.

The objectAtIndex: method has the following syntax:

[shoeOrder objectAtIndex: /* INSERT INDEX HERE */];

Putting the two methods together, each line of code adding a key-value pair should look like this:

[shoeOrderDict setValue: [shoeOrder objectAtIndex: /* INSERT INDEX HERE */] forKey: /* INSERT KEY HERE */];

I hope this helps!

Christian A. Castro
Christian A. Castro
30,501 Points

Andre Robinson ..

NSMutableDictionary *shoeOrderDict = [[NSMutableDictionary alloc]initWithObjectsAndKeys:
                                      [shoeOrder objectAtIndex:0], @"customer",
                                      [shoeOrder objectAtIndex:1], @"size",
                                      [shoeOrder objectAtIndex:2], @"style",
                                      [shoeOrder objectAtIndex:3], @"color",
                                      nil];

hope this helps you!!!