Question

I’ve the following array containing other arrays.

NSArray *results = [[NSArray alloc] initWithObjects:
[NSArray arrayWithObjects:@"Nickname1", [NSNumber numberWithBool:YES], nil],
[NSArray arrayWithObjects:@"Nickname2", [NSNumber numberWithBool:NO], nil],
[NSArray arrayWithObjects:@"Nickname3", [NSNumber numberWithBool:YES], nil],
[NSArray arrayWithObjects:@"Nickname4", [NSNumber numberWithBool:YES], nil],
nil ];

How do I sort the elements of this array by the second parameter (the boolean one). can I use NSSortDescriptor ? (I want all YES before).

thanks

Answer 1

You can use the sortedArrayUsingComparator method for this. Since you want the YES values (a constant of value 1) sorted before the NO values (a constant value of 0), just reverse the order of the objects in the compare: call.

NSArray *sortedArray = [results sortedArrayUsingComparator:^(id o1, id o2) {
    NSArray *ary1 = (NSArray *)o1;
    NSArray *ary2 = (NSArray *)o2;

    return [[ary2 objectAtIndex:1] compare:[ary1 objectAtIndex:1]];
}];