Check if NSDictionary is empty

Question

I want to check if an NSDictionary is empty. I am doing it like this.

  mutDictValues = [[[NSUserDefaults standardUserDefaults] objectForKey:@"dicValues"]mutableCopy];
    NSLog(@"dictValues are %@",mutDictValues);
    if(mutDictValues == NULL){
        arrCities = [[NSMutableArray alloc]init];
        NSLog(@"no cities seleceted");
    }else{
          arrCities = [[NSMutableArray alloc]init];
          arrCities = [mutDictValues objectForKey:@"cities"];
          [self placeCities];
    }

But it alwasy crashes on this line arrCities = [mutDictValues objectForKey:@"cities"]; with the following error:

-[__NSCFConstantString objectForKey:]:

Can someone help me with this ?

Solution 1

While retrieving the dictionary values from NSUserDefaults that dictionary automatically converted into string that is the reason for getting crashed and for 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"]);

Solution 2

if ( [mutDictValues count] == 0 ) {
    //code here
}
else {
    //code here
}

After having your dic retrieved this should do

Solution 3

try this,

if([myDict count] > 0)
    NSLog(@"Dictionary is not empty");
else
    NSLog(@"Dictionary is empty");

Solution 4

BOOL containsKeyABC = [myDict: valueForKey:@"ABC"];

int items = dict.count;

if (items > 0) {
     //not empty
}

Solution 5

Somewhere you treat a nsstring (a concrete subclass) as NSdictionary.

View more solutions

Comments

[Steaphann]

Is it possible to get this back as NSDictionary ?

[Balu]

once check this one,stackoverflow.com/questions/6797096/…

[kb920]

if (![dictTemp isKindOfClass:[NSDictionary class]]) { // do something DisplayAlert(@"No data found") }