Char.IsDigit() is a subset of Char.IsNumber().
Some of the characters that are ‘numeric‘ but not digits include 0x00b2 and 0x00b3 which are superscripted 2 and 3 (‘²‘ and ‘³‘) and the glyphs that are fractions such as ‘¼‘, ‘½‘, and ‘¾‘.
Note that there are quite a few characters that IsDigit() returns true for that are not in the ASCII range of 0x30 to 0x39, such as these Thai digit characters: ‘?‘ ‘?‘ ‘?‘ ‘?‘ ‘?‘ ‘?‘ ‘?‘ ‘?‘ ‘?‘ ‘?‘.
This snippet of code tells you which code points differ:
static private void test() { for (int i = 0; i <= 0xffff; ++i) { char c = (char) i; if (Char.IsDigit( c) != Char.IsNumber( c)) { Console.WriteLine( "Char value {0:x} IsDigit() = {1}, IsNumber() = {2}", i, Char.IsDigit( c), Char.IsNumber( c)); } } }
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