How to calculate total size of NSDictionary object?

Question

How to calculate total size of NSDictionary object? i have 3000 StudentClass objects in NSDictionary with different keys. And i want to calculate total size of dictionary in KB. I used malloc_size() but it always return 24 (NSDictionary contain either 1 object or 3000 object) sizeof() also returns always same.

Answer 1

You can also find this way:

Objective C

NSDictionary *dict=@{@"a": @"Apple",@"b": @"bApple",@"c": @"cApple",@"d": @"dApple",@"e": @"eApple", @"f": @"bApple",@"g": @"cApple",@"h": @"dApple",@"i": @"eApple"};

NSMutableData *data = [[NSMutableData alloc] init];
NSKeyedArchiver *archiver = [[NSKeyedArchiver alloc] initForWritingWithMutableData:data];
[archiver encodeObject:dict forKey:@"dictKey"];
[archiver finishEncoding];

NSInteger bytes=[data length];
float kbytes=bytes/1024.0;
NSLog(@"%f Kbytes",kbytes);

Swift 4

let dict: [String: String] = [
    "a": "Apple", "b": "bApple", "c": "cApple", "d": "dApple", "e": "eApple", "f": "bApple", "g": "cApple", "h": "dApple", "i": "eApple"
]

let data = NSMutableData()
let archiver = NSKeyedArchiver(forWritingWith: data)
archiver.encode(dict, forKey: "dictKey")
archiver.finishEncoding()

let bytes = data.length
let kbytes = Float(bytes) / 1024.0

print(kbytes)

Answer 2

You could try to get all the keys of the Dictionary in an array and then iterate the array to find the size, it might give you the total size of the keys inside the dictionary.

NSArray *keysArray = [yourDictionary allValues];
id obj = nil;
int totalSize = 0;

for(obj in keysArray)
{
    totalSize += malloc_size(obj);
}