array sorting error in objective c

Question

I have 4 values in my NSDictionary below which are 1000,640,80 and 0 It sorts the non-zero values correctly but it always gives 0 as greater than all the other values like (descending): 0,1000,640,80 Here's the code:

    NSMutableDictionary *dict = [[self model] stateFromDocumentNamed:@"state"];
    NSArray *values=[dict allValues];
    NSMutableArray *mutvalues = [(NSArray*)values mutableCopy];
    [mutvalues sortUsingSelector:@selector(compare:)];
    values=[[values reverseObjectEnumerator] allObjects];
    NSLog(@"%@",mutvalues);

0 comes before 1. 0 < 1 < 6 < 8. You would get the same result if you used 0, 1, 6, 8 rather than 1000, 640, and 80. In which case they'd be in order. — nhgrif
– nhgrif, Commented Mar 11, 2014 at 23:39

Wain · Accepted Answer · 2014-03-11 23:41:36Z

5

Presumably you are comparing strings which contain numbers. To have the sort work as you expect with the numbers you will want to use the NSNumericSearch option (in the method compare:options:, probably used with sortedArrayUsingComparator:).

answered Mar 11, 2014 at 23:41

Wain

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Merlevede · Accepted Answer · 2014-03-11 23:41:49Z

3

This is probably because the objects in your NSMutableDictionary are strings instead of numbers. Possible solutions:

You would need to convert all objects to numbers
Use a different selector to sort
sort using a block, using sortedArrayUsingComparator
EDIT: sort using method proposed in Wain's answer

answered Mar 11, 2014 at 23:41

Merlevede

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