NSMutableDictionary may not respond to '-setValue:forKey:'

Question

Getting "NSMutableDictionary may not respond to '-setValue:forKey:'" error from this code:

NSMutableDictionary *parameters = [[[NSMutableDictionary alloc] init] autorelease];
MKFacebookRequest *request = [MKFacebookRequest requestWithDelegate:self];

//set up parameters for request
[parameters setValue:[NSArray arrayWithObjects:[fbConnection uid], @"123456789", nil] forKey:@"uids"];
[parameters setValue:[NSArray arrayWithObjects:@"first_name",@"last_name",nil] forkey:@"fields"];

//send the request
[request sendRequest:@"users.getInfo" withParameters:parameters];

Any ideas?

Console Error:

2010-08-12 15:23:45.419 App[322:a0f] -[NSCFDictionary setObject:forkey:]: unrecognized selector sent to instance 0x46fa00
2010-08-12 15:23:45.419 App[322:a0f] -[NSCFDictionary setObject:forkey:]: unrecognized selector sent to instance 0x46fa00

Answer 1

forKey: not forkey:

also, the proper method to use for NSMutableDictionary is setObject:forKey:

Answer 2

Are you sure the error message is not reporting that "NSMutableDictionary may not respond to '-setValue:forkey:'"?
Objective-C is case sensitive.

NsMutableDictionary has both the metods -setValue:forKey:, and -setObject:forKey:; the difference is that, if the value passed as first parameter to -setValue:forKey: is nil, then the method will remove the key using -removeObjectForKey:.