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iOS

Posted by NAUSHAD DARUWALLA
NAUSHAD DARUWALLA
1,587 Points

Sorting NSMutableArray by using NSInteger property of an object

Hello all, I am trying to sort an NSMutableArray in descending order based on an NSInteger value of the object that is in the array. The object name is homeworkItem, the array name is homeworkObjectItem and the NSInteger that I'm trying to sort by is baseRankNumber. How would I do this? Thank you!

4 Answers

chriscameron
chriscameron
15,397 Points
chriscameron
chriscameron
15,397 Points

Now, I haven't tried this out for myself, but rosettacode gives a snippet where you might be able to start. http://rosettacode.org/wiki/Sort_an_integer_array#Objective-C

NAUSHAD DARUWALLA
NAUSHAD DARUWALLA
1,587 Points
NAUSHAD DARUWALLA
NAUSHAD DARUWALLA
1,587 Points

But this approach is for when you have used NSNumber and I have used NSInteger. How else can I do it and for NSInteger?

chriscameron
chriscameron
15,397 Points
chriscameron
chriscameron
15,397 Points

Ok so what have you got your NSInteger * "named" as?

Basically from what I've found, you may need to change the NSInteger to an NSNumber. The questioners code at the top does this, but remember to set your array. http://stackoverflow.com/questions/8600841/adding-nsinteger-object-to-nsmutablearray

NAUSHAD DARUWALLA
NAUSHAD DARUWALLA
1,587 Points
NAUSHAD DARUWALLA
NAUSHAD DARUWALLA
1,587 Points

Ok so this is what i tried to sort the baseRankNumber property for each homeworkObject in the homeworkObjectItem array, but when I enter the second homework item, it crashes. What is wrong about this?

[self.homeworkObjectItem addObject:source.homeworkItem]; NSSortDescriptor *sortDescriptor; sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"baseRankNumber" ascending:YES]; NSArray *sortDescriptors = [NSArray arrayWithObject:sortDescriptor]; NSArray *sortedArray; sortedArray = [self.homeworkObjectItem sortedArrayUsingDescriptors:sortDescriptors]; [self.tableView reloadData];