Question

I am saving some files in document directory through my app using custom naming as “file1.format” ,”file2.format” and so on.Later I fetch these files in an Array and printing them in a loop then they are coming in sorted form but the problem arises when I store “file10.format” and so on. After this the result comes is some what unexpected. As after saving 10th file the output comes like

file1.foramt
file10.format
file2.format
.
.
file6.format
file61.format
file7.format
I don’t know why sorting take all 1s or 2s on one place as shown above while it is expected that 10 should just comes after 9 not after 1.I used all kind of sorting but the result is coming same all time.

Answer 1

If you want to sort file names “as the Finder does”, use localizedStandardCompare. In particular, numbers in the strings are sorted according to their numeric value:

NSArray *files = [NSArray arrayWithObjects:@"file10.format", @"file2.format", @"file1.format", nil];
NSArray *sorted = [files sortedArrayUsingSelector:@selector(localizedStandardCompare:)];
NSLog(@"%@", sorted);

Output:

2012-11-05 11:38:55.474 test77[533:403] (
    "file1.format",
    "file2.format",
    "file10.format"
)