Question

Iam developing an iPad application, It has a tableview with custom cells.
Each cell is an object which represents the properties of the class in 3 columns.
I want to sort the data based on the columns. How can I achieve it using objective c?

Answer 1

You can use a NSSortDescriptor to do this job.

Prepare the array that needs sorting

NSArray *objects = [[NSArray alloc] initWithObjects:obj1, obj2, obj3, nil];

Create an array with NSSortDescriptors, in this example I use 1. For the DescriptorKey, take a property from the Cell on which you would like the sorting to be based upon.

NSArray *descriptor = [NSArray arrayWithObject:[NSSortDescriptor sortDescriptorWithKey:@"title" ascending:YES]];

Then instantiate a new array and call the sortedArrayUsingDescriptors instance method from NSArray, on your initial array, returning a sorted array with the same objects.

NSArray *sortedArray = [objects sortedArrayUsingDescriptors:descriptor];

Hope this helps!