compare:options: How to sort symbols before numbers?

Question

I'm currently using this compare options to sort a list of strings:

 [self compare:aString options:NSNumericSearch|NSCaseInsensitiveSearch];

However, numbers come before than symbols:

99
[Hello
Hello

Is there a way to sort symbols before numbers ? thanks

There should be some useful information in the answers to this question: http://stackoverflow.com/questions/9327997/dictionary-key-sort-options-alpha-then-numeric — Monolo, Jun 13 '12 at 09:23

score 0 · Accepted Answer · answered Jun 13 '12 at 08:01

Not all symbols come before numbers in the ASCII table, which is why you noticed this behaviour with '['. Assuming self in your example is an NSArray, you'll need to use the sortedArrayUsingComparator: method and implement a custom sorter. (Other classes besides NSArray will have this method as well.)

NSComparator sortBlock = ^(id string1, id string2)
{
    // Fill this in
};

NSArray* sortedArray = [originalArray sortedArrayUsingComparator:sortBlock];

Check out Getting Started with Blocks on Apple's developer site.

compare:options: How to sort symbols before numbers?

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