Sort NSArray having NSData array

Question

i have this nsarray having images data in it images setting dynamically in array but i want to filter data if there is any nil nsdata i dont want it inside my nsarray how can i sort this array. here is my code.

NSData* imageData = [[NSUserDefaults standardUserDefaults] objectForKey:@"profileImg"];
    NSData* imageData1 = [[NSUserDefaults standardUserDefaults] objectForKey:@"profileImg1"];
    NSData* imageData2 = [[NSUserDefaults standardUserDefaults] objectForKey:@"profileImg2"];
    NSData* imageData3 = [[NSUserDefaults standardUserDefaults] objectForKey:@"profileImg3"];
    NSData* imageData4 = [[NSUserDefaults standardUserDefaults] objectForKey:@"profileImg4"];
    NSData* imageData5 = [[NSUserDefaults standardUserDefaults] objectForKey:@"profileImg5"];




    self.pageImages = [NSArray arrayWithObjects:
                                           [UIImage imageWithData:imageData],
                                           [UIImage imageWithData:imageData1],
                                           [UIImage imageWithData:imageData2],
                                           [UIImage imageWithData:imageData3],
                                           [UIImage imageWithData:imageData4],
                                           [UIImage imageWithData:imageData5],nil];

There can't be nil objects in an NSArray. If, for example, imageData1 is nil, the array will only contain imageData and no other images. — rmaddy
– rmaddy, Commented Aug 10, 2016 at 15:45
So if i put some other dummy pic instead of nil so will it work then?? I mean how can i apply if statement on is image is dummy then DONOT add is in nsaray! — Vix Hunk
– Vix Hunk, Commented Aug 10, 2016 at 15:51

rmaddy · Accepted Answer · 2016-08-11 06:41:57Z

3

I would take a completely different approach. The problem is that arrayWithObjects: stops when it encounters a nil. If, for example, imageData1 is nil, your array will only have one image - imageData.

A better way would be to check each one for nil. Only add the non-nil images.

NSArray *keys = @[ @"profileImg", @"profileImg1", @"profileImg2", @"profileImg3", @"profileImg4", @"profileImg5" ];
NSMutableArray *images = [NSMutableArray array];
for (NSString *key in keys) {
    NSData* imageData = [[NSUserDefaults standardUserDefaults] objectForKey:key];
    if (imageData) {
        UIImage *image = [UIImage imageWithData:imageData];
        if (image) {
            [images addObject:image];
        }
    }
}

self.pageImages = [images copy];

edited Aug 11, 2016 at 6:41

answered Aug 10, 2016 at 15:57

rmaddy

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1 Comment

Vix Hunk Over a year ago

triend this one but app crashes and output "*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSCFData _isDecompressing]: unrecognized selector sent to instance 0x1567164a0'"

Larme · Accepted Answer · 2016-08-10 13:40:14Z

1

You can directly check whether the object at that index is nil.

NSMutableArray * finalArray = [[NSMutableArray alloc] init];
for (int i = 0; i< pageImages.count; i++) {
    if (pageImages[i]){
        UIImage * temp = [pageImages objectAtIndex:i];
        [finalArray addObject:temp];
    }
}

edited Aug 10, 2016 at 13:40

Larme

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answered Aug 10, 2016 at 13:38

Shubham Daramwar

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11 Comments

Vix Hunk Over a year ago

thanks for replying i actually want to store sorted data inside the same self.pageImages

Vix Hunk Over a year ago

i actually want to exclude all the images with nill data or no images in it out of my nsarray

Shubham Daramwar Over a year ago

Yes, that's what I am saying . take the finalArray and store in pageImages

Shubham Daramwar Over a year ago

Add after for loop - pageImages = finalArray ;

Vix Hunk Over a year ago

i did that but still no luck :(

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