sorting a nested NSMutableArray - ios

Question

the NSMutableArray I want to sort looks like this:
(
{
"title" = "Bags";
"price" = "$200";
},
{
"title" = "Watches";
"price" = "$40";
},
{
"title" = "Earrings";
"price" = "$1000";
}
)
It's an NSMutableArray which contain a collection of NSMutableArrays. I want to sort it by price first then by title.
NSSortDescriptor *sortByPrices = [[NSSortDescriptor alloc] initWithKey:#"price" ascending:YES];
NSSortDescriptor *sortByTitle = [[NSSortDescriptor alloc] initWithKey:#"title" ascending:YES];
[arrayProduct sortedArrayUsingDescriptors:[NSArray arrayWithObjects:sortByPrices,sortByTitle,nil]];
However, that didn't seems to work, how to sort a nested NSMutableArray?

Answer 1

Try
NSMutableArray *arrayProducts = [#[#{#"price":#"$200",#"title":#"Bags"},#{#"price":#"$40",#"title":#"Watches"},#{#"price":#"$1000",#"title":#"Earrings"}] mutableCopy];
NSSortDescriptor *priceDescriptor = [NSSortDescriptor sortDescriptorWithKey:#""
ascending:YES
comparator:^NSComparisonResult(NSDictionary *dict1, NSDictionary *dict2) {
return [dict1[#"price"] compare:dict2[#"price"] options:NSNumericSearch];
}];
NSSortDescriptor *titleDescriptor = [NSSortDescriptor sortDescriptorWithKey:#"title" ascending:YES];
[arrayProducts sortUsingDescriptors:#[priceDescriptor,titleDescriptor]];
NSLog(#"SortedArray : %#",arrayProducts);

Answer 2

I suppose the error is that price is a string. As such, it isn't compared numerically, but lexicographically. Try sorting the array using a comparator block and parsing the price inside that block instead:
[array sortUsingComparator:^(id _a, id _b) {
NSDictionary *a = _a, *b = _b;
// primary key is the price
int priceA = [[a[#"price"] substringFromIndex:1] intValue];
int priceB = [[b[#"price"] substringFromIndex:1] intValue];
if (priceA < priceB)
return NSOrderedAscending;
else if (priceA > priceB)
return NSOrderedDescending;
else // if the prices are the same, sort by name
return [a[#"title"] compare:b[#"title"]];
}];

Answer 3

Try this
Apple doc
This well help you