iphone - Check if NSDictionary is empty -

i want check if nsdictionary empty. doing this.

  mutdictvalues = [[[nsuserdefaults standarduserdefaults] objectforkey:@"dicvalues"]mutablecopy];     nslog(@"dictvalues %@",mutdictvalues);     if(mutdictvalues == null){         arrcities = [[nsmutablearray alloc]init];         nslog(@"no cities seleceted");     }else{           arrcities = [[nsmutablearray alloc]init];           arrcities = [mutdictvalues objectforkey:@"cities"];           [self placecities];     } 

but alwasy crashes on line arrcities = [mutdictvalues objectforkey:@"cities"]; following error:

-[__nscfconstantstring objectforkey:]: 

can me ?

while retrieving dictionary values nsuserdefaults dictionary automatically converted string reason getting crashed , checking dictionary use

[dictionary count]; 

edit:- use dictionaryforkey: method

nsdictionary *dict =[[nsdictionary alloc]initwithobjectsandkeys:@"hi",@"one",nil]; [[nsuserdefaults standarduserdefaults] setobject:dict forkey:@"dic"]; nsdictionary *dictn = [[nsuserdefaults standarduserdefaults] dictionaryforkey:@"dic"]; nslog(@"%@",[dictn objectforkey:@"one"]);