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iOS Object-Oriented Objective-C Memory, Arrays and Loops, Oh My! Alloc and Init

How to declare an NSMutableDictionary?

hai,what wrong with my code,how to write ,I dont konw ,give me some help,thank you.

variable_assignment.mm
NSMutableDictionary *carDict = [NSMutableDictionary alloc];
[carDict initwithObjectsAndKeys:@"Honda",@"Make",@"Accord",@"Model",nil];

2 Answers

Amit Bijlani
STAFF
Amit Bijlani
Treehouse Guest Teacher

You are almost right. Firstly, the method names are case sensitive so make sure you are using the right capitalization. Your method nameinitwithObjectsAndKeys should be with a capital i.

Secondly, you want to declare it all in one line:

NSMutableDictionary *carDict = [[NSMutableDictionary alloc] initWithObjectsAndKeys:@"Honda",@"Make",@"Accord",@"Model",nil];

ok,Thank you,but Mr Amit Bijlani,how should I write on the third step,I dont know how to write on the three step. NSMutableDictionary *carDict = [[NSMutableDictionary alloc] initWithObjectsAndKeys:@"Honda",@"Make",@"Accord",@"Model",nil];

NSString *myRide = [[NSString alloc] init]; Thank you for your answer.

Amit Bijlani
STAFF
Amit Bijlani
Treehouse Guest Teacher

The third step says: "Set the value of 'myRide' to the value of "Make" contained in 'carDict'."

What it is asking you to do is assign the value of the key Make contained in the dictionary variable named carDict to the variable myRide. You need to use the method to get the value out of the dictionary. You need to use the method valueForKey to get the value out of the dictionary.