Sort NSMutableArray based on strings from another NSArray

Question

I have an NSArray of strings that I want to use as my sort order:

NSArray *permissionTypes = [NSArray arrayWithObjects:@"Read", @"Write", @"Admin", nil];

I then have a NSMutableArray that may or may not have all three of those permissions types, but sometimes it will only be 2, sometimes 1, but I still want it sorted based on my permissionsTypes array.

NSMutableArray *order = [NSMutableArray arrayWithArray:[permissions allKeys]];

How can I always sort my order array correctly based on my using the permissionTypes array as a key?

You could use NSSortDescriptor and/or blocks, as described here. — lindon fox
– lindon fox, Commented Dec 3, 2012 at 9:12
you can make use of the methods sortUsingSelector: or sortUsingComparator:, in this other question you can find more information stackoverflow.com/questions/1132806/… — tkanzakic
– tkanzakic, Commented Dec 3, 2012 at 9:14

Fogmeister · Accepted Answer · 2012-12-03 09:13:37Z

3

I would go about this by creating a struct or an object to hold the permission types.

Then you can have...

PermissionType
--------------
Name: Read
Order: 1

PermissionType
--------------
Name: Write
Order: 2

and so on.

Then you only need the actual array of these objects and you can sort by the order value.

[array sortUsingComparator:^NSComparisonResult(PermissionType *obj1, PermissionType *obj2) {
        return [obj1.order compare:obj2.order];
    }];

This will order the array by the order field.

edited Dec 3, 2012 at 9:13

answered Dec 3, 2012 at 9:07

Fogmeister

77.8k45 gold badges217 silver badges322 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

Nic Hubbard Over a year ago

I don't think it is that easy though. Even though I want Write in position 1, if the array I get only has 1 string in it, which is "Write", then obviously it would need to be in position 0.

Fogmeister Over a year ago

The "Order" value is only a sorting value. not an absolute position. I'll add the sort code...

Nic Hubbard Over a year ago

Shouldn't this also work? [order sortUsingComparator:^NSComparisonResult(NSString *obj1, NSString *obj2) { return [[NSNumber numberWithInt:[permissionTypes indexOfObject:obj1]] compare:[NSNumber numberWithInt:[[permissions allKeys] indexOfObject:obj2]]]; }];

pbibergal · Accepted Answer · 2012-12-03 09:14:18Z

3

NSMutableArray *sortDescriptors = [NSMutableArray array]; 

for (NSString *type in permissionTypes) {
    NSSortDescriptor *descriptor = [[[NSSortDescriptor alloc] initWithKey:type ascending:YES] autorelease];

    [sortDescriptors addObject:descriptor];
}

sortedArray = [myArray sortedArrayUsingDescriptors:sortDescriptors];

answered Dec 3, 2012 at 9:14

pbibergal

2,9211 gold badge19 silver badges19 bronze badges

Comments

CRD · Accepted Answer · 2012-12-03 09:11:33Z

0

Use whichever sorting method on NSMutableArray you prefer, you will either provide a block or a selector to use for comparing two elements. In that block/selector rather than comparing the two strings passed in directly look each up in your permissionTypes array using indexOfObject: and compare the resulting index values returned.

answered Dec 3, 2012 at 9:11

CRD

53k5 gold badges73 silver badges87 bronze badges

Comments

sundsx · Accepted Answer · 2013-04-18 14:56:20Z

0

I suggest you another approuch:

- (void)viewDidLoad
{
[super viewDidLoad];

arrayPermissions = [[NSMutableArray alloc] init];


NSDictionary *dicRead = [NSDictionary dictionaryWithObjectsAndKeys:
                              @"Read", @"Permission", nil];

NSDictionary *dicWrite = [NSDictionary dictionaryWithObjectsAndKeys:
                               @"Write", @"Permission", nil];

NSDictionary *dicAdmin = [NSDictionary dictionaryWithObjectsAndKeys:
                              @"Admin", @"Permission", nil];

NSLog(@"my dicRead = %@", dicRead);
NSLog(@"my dicWrite = %@", dicWrite);
NSLog(@"my dicAdmin = %@", dicAdmin);

[arrayPermissions addObject:dicRead];
[arrayPermissions addObject:dicWrite];
[arrayPermissions addObject:dicAdmin];

NSLog(@"arrayPermissions is: %@", arrayPermissions);

// create a temporary Dict again

NSDictionary *temp =[[NSDictionary alloc]
                     initWithObjectsAndKeys: arrayPermissions, @"Permission", nil];

// declare one dictionary in header class for global use and called "filteredDict"
self.filteredDict = temp;

self.sortedKeys =[[self.filteredDict allKeys]
                  sortedArrayUsingSelector:@selector(compare:)];


NSLog(@"sortedKeys is: %i", sortedKeys.count);
NSLog(@"sortedKeys is: %@", sortedKeys);

}

hope help

answered Apr 18, 2013 at 14:56

sundsx

61811 silver badges29 bronze badges

8 Comments

vikingosegundo Over a year ago

why are people so afraid about writing custom classes? it is kind of stupid to hold an extra array for the sorted keys if you just can stick the custom objects into an array and sort that.

sundsx Over a year ago

Think before you say that. I see only one Array, perhaps too many dictionaries, but if you know the method that you suggest would not have asked. My suggestion is easy to understand and can be optimized once you understand the mechanics. Anyway, I appreciate your suggestion ...

vikingosegundo Over a year ago

btw: how is sortedKeys helpful? it just contain one key.

sundsx Over a year ago

do you like more? NSArray *sortedArrayXX; NSArray *permissionTypes = [NSArray arrayWithObjects:@"Read", @"Write", @"Admin", nil]; sortedArrayXX = [permissionTypes sortedArrayUsingSelector:@selector(compare:)]; NSLog(@"This is sortedArrayXX: %@", sortedArrayXX);

vikingosegundo Over a year ago

Why sort an array, that only has one entry? do u want to put this object on the start or on the end?

|

Collectives™ on Stack Overflow

Sort NSMutableArray based on strings from another NSArray

4 Answers 4

3 Comments

Comments

Comments

8 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

4 Answers 4

3 Comments

Comments

Comments

8 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related