如何比较两个字典

Question

I have two array of dictionaries and i want to compare them

Actually the dictionary structure is like the interest list of Facebook, like below

I want to find out the common interest between me and my friend

I retrieved the interest list of both user, but while I am comparing the dictionary of interests as the created_time differs so I am not getting the common dictionary

        category = "Musical instrument";
        "created_time" = "2011-06-11T09:10:07+0000";
        id = 113099055370169;
        name = Guitar;

and

            category = "Musical instrument";
            "created_time" = "2013-09-27T06:02:28+0000";
            id = 113099055370169;
            name = Guitar;

Can anybody suggest any efficient way to do this

Now I am using but it is not giving me the common interests as created_time different

for (int count = 0; count < [arrFriendsInterest count]; count++)
{
    NSDictionary *dictFriend = [arrFriendsInterest objectAtIndex:count];

    if ([arrMyIntrest containsObject:dictFriend]) {
        [arrMutualInterest addObject:dictFriend];
    }

}

where arrFriendsInterest is array of dictionaries containing friend's interest

and arrMyIntrest is the array of dictionaries containing my interests×Comments may only be edited for 5 minutes×Comments may only be edited for 5 minutes×Comments may only be edited for 5 minutes

Answer 1

First of all are you store that data in NSArray?

If YES then please use following code much more easily to use.

// Do any additional setup after loading the view, typically from a nib.
NSArray *ar1 = [NSArray arrayWithObjects:[NSDictionary dictionaryWithObjectsAndKeys:@"Musical instrument",@"category",@"2011-06-11T09:10:07+0000",@"created_time",@"113099055370169",@"id", @"Guitar",@"name", nil], nil];


NSArray *ar2 = [NSArray arrayWithObjects:[NSDictionary dictionaryWithObjectsAndKeys:@"Musical instrument",@"category",@"2013-09-27T06:02:28+0000",@"created_time",@"113099055370169",@"id", @"Guitar",@"name", nil], nil];

NSMutableSet* set1 = [NSMutableSet setWithArray:ar1];
NSMutableSet* set2 = [NSMutableSet setWithArray:ar2];
[set1 unionSet:set2]; //this will give you only the obejcts that are in both sets

NSArray* result = [set1 allObjects];
NSLog(@"%@",[result mutableCopy]);

Happy Coding.!!!

Answer 2

This assumes that you only need to compare "id" values:

NSArray* myIds = [arrMyInterest valueForKey:@"id"];

for (int count = 0; count < [arrFriendsInterest count]; count++) {
    NSDictionary *dictFriend = [arrFriendsInterest objectAtIndex:count];

    // Not clear whether "id" is NSString or NSNumber -- use whichever
    NSString* friendId = [dictFriend valueForKey:@"id"];
    if ([myIds containsObject:friendId]) {
         [arrMutualInterest addObject:dictFriend];
    }
}

Answer 3

instead of using NSDictionary why don't using custom classes?

You can have a lot of benefits:

• code completion
• compile-time checking
• custom isEqual method
• code is self-explained