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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
Posted by Andre Robinson
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
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
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!!!