Question

I accessed the Data from sqlite file as NSMutableArray[model_Array] in which I have duplicates info [two/three] so i wanna delete that, I tried to assign the MutableArray to another NSMutableArray[allItems] by two different idea given below

AppDelegate *readTheDatabase = (AppDelegate *)[[UIApplication sharedApplication] delegate]; 

allItems = [[NSMutableArray alloc] initWithArray:readTheDatabase.model_Array];  
NSSet *uniqueItems; 
uniqueItems = [NSSet setWithArray:allItems];

or

NSMutableArray *uniqueItems = [NSMutableArray array];
for (id item in allItems)
    if (![uniqueItems containsObject:item])
        [uniqueItems addObject:item];

---

but it is unable to delete the duplicate data. please anyone help and suggest me to overcome this problem. Thanks in advance.

Answer 1

Your objects within the array are obviously not returning true for the isEqual: method.

What kind of object does the array contain?

I assume it’s some custom model class that represents the data in the database.

You should look up the documentation for NSObject and the isEqual: and hash: methods.

You will learn how to express when two objects are equal, which is how NSArray and NSSet etc determine whether objects are already contained within the collection.