Compare 2 NSMutableArrays and remove duplicate records

Question

I have 2 NSMutableArrays. They are:

allStudentsMutableArr
selectedStudentsMutableArr

allStudentsMutableArr contains all the Student objects and it has around 100 objects saved in it. Whereas, selectedStudentsMutableArr only contains 10 Student records saved in it.

Now i need to compare the 2 MutableArrays and remove all objects from allStudentsMutableArr that's present in selectedStudentsMutableArr mutable array. How can i do this ?

possible duplicate of [NSArray with NSPredicate using NOT IN](http://stackoverflow.com/questions/8580715/nsarray-with-nspredicate-using-not-in) — Paulw11, Mar 17 '15 at 11:03
`NSMutableSet` and `–minusSet:`... IMHO is the best way to do such thing. — holex, Mar 17 '15 at 11:24

score 2 · Accepted Answer · answered Mar 17 '15 at 11:03

2

Simple

[allStudentsMutableArr removeObjectsInArray:selectedStudentsMutableArr];

answered Mar 17 '15 at 11:03

Nirav Gadhiya

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Thanks. This sorted it. I will accept this as an answer shortly. – Illep Mar 17 '15 at 11:08
Welcome and feel free to ask for any other help. – Nirav Gadhiya Mar 17 '15 at 11:09

score 0 · Answer 2 · answered Mar 17 '15 at 11:16

You can also use NSPredicate as below...(Gadhiya solution also useful..)

Suppose you have student object with name as one of property then..//or any property that you want to compare and filter..

NSPredicate *filterPredicate = [NSPredicate predicateWithFormat: @"!(name IN %@)", selectedStudentsMutableArr];
NSArray* filteredArray = [allStudebtsMutableArr filteredArrayUsingPredicate:filterPredicate];

Hope it helps you..

Compare 2 NSMutableArrays and remove duplicate records

2 Answers2