Sort a char array case-insensitively

[Paul E Collins]

char[] c = { 'a', 'b', 'c', 'A', 'B', 'C' };
Array.Sort(c, CaseInsensitive Comparer.Defaul t);

After this, c is ordered { 'A', 'B', 'C', 'a', 'b', 'c' }.

I want letters to be sorted together regardless of case, e.g. 'A' next to
'a'.

Why doesn't that case-insensitive sort work? What should I do instead?

Eq.

[Jeroen Mostert]

Re: Sort a char array case-insensitively

Paul E Collins wrote:

char[] c = { 'a', 'b', 'c', 'A', 'B', 'C' };
Array.Sort(c, CaseInsensitive Comparer.Defaul t);
>
After this, c is ordered { 'A', 'B', 'C', 'a', 'b', 'c' }.
>
I want letters to be sorted together regardless of case, e.g. 'A' next to
'a'.
>
Why doesn't that case-insensitive sort work? What should I do instead?
>

CaseInsensitive Comparer operates on strings only, not characters. I don't
think the framework has lexicographical comparers for characters out of the box.

The most straightforward way to achieve what you want is to use a
Comparison<Ttha t lifts its arguments to strings:

Array.Sort(c, (a, b) =string.Compare (a.ToString(), b.ToString(),
StringCompariso n.CurrentCultur eIgnoreCase));

There may be a more elegant way.

--
J.

[=?ISO-8859-1?Q?G=F6ran_Andersson?=]

Re: Sort a char array case-insensitively

Paul E Collins wrote:

char[] c = { 'a', 'b', 'c', 'A', 'B', 'C' };
Array.Sort(c, CaseInsensitive Comparer.Defaul t);
>
After this, c is ordered { 'A', 'B', 'C', 'a', 'b', 'c' }.
>
I want letters to be sorted together regardless of case, e.g. 'A' next to
'a'.
>
Why doesn't that case-insensitive sort work?

Because the CaseInsensetive Comparer compares strings, and if you use it
to compare something different, it will fallback to using
Comparer.Defaul t.Compare() instead.

What should I do instead?

You can make your own comparer that turns the characters to lower case
and compares them:

Array.Sort(c, (x, y) =char.ToLower(x ) - char.ToLower(y) );

or

Array.Sort(c, delegate(char x, char y) { return char.ToLower(x) -
char.ToLower(y) ; });

--
Göran Andersson
_____

http://www.guffa.com