ios - Sorting NSArray of dictionaries by value of a key in the dictionaries

Question

I have an array populated by dictionaries, and I need to sort the array alphabetically by the values of one of the keys of the dictionaries.

This is my array:

tu dictus: (
    {
    brand = Ryul;
    productTitle = Any;
    quantity = 1;
    subBrand = "Ryul INJ";
    type = Product;
},
    {
    brand = Trol;
    productTitle = Different;
    quantity = 2;
    subBrand = "";
    type = Brand;
},
    {
    brand = Dtor;
    productTitle = Any;
    quantity = 1;
    subBrand = "";
    type = Product;
},
    {
    brand = Ryul;
    productTitle = Different;
    quantity = 2;
    subBrand = "Ryul CHES";
    type = SubBrand;
},
    {
    brand = Anan;
    productTitle = Any;
    quantity = 1;
    subBrand = "";
    type = Product;
}
)

Normally for sorting an array I will use

myArray = [uniqueProdsArray sortedArrayUsingSelector:@selector(localizedCaseInsensitiveCompare:)];

But how do sort using the brand key of the dictionary?

Answer 1

I think this will do it:

brandDescriptor = [[NSSortDescriptor alloc] initWithKey:@"brand" ascending:YES];
sortDescriptors = [NSArray arrayWithObject:brandDescriptor];
sortedArray = [myArray sortedArrayUsingDescriptors:sortDescriptors];

I pulled the code from Sort Descriptor Programming Topics. Also, Key-Value Coding comes into play, in that sortedArrayUsingDescriptors: will send a valueForKey: to each element in myArray, and then use standard comparators to sort the returned values.