Differences between Japanese Number Formats

Question

In .NET, I need (if possible) to distinguish between different types of Japanese number strings.

In Japanese numbers, numbers can be written in different ways, for example, for "1" there are characters "1" , "ⅰ" , "Ⅰ" , "①" in half-width characters.

I need to compare strings like "MyString1" and "MyString①" , and for obvious reasons they are not equal. I am wondering if there is a way to automatically change characters like "①" to "1" automatically?

EDIT

I know that the obvious answer would be to make a list of all possible characters like "(" (their finite number) and replace them in the target line. But this is not a very “good” way to get around this, in my opinion, and not very reliable ... therefore, if there is a general way, I would rather use this.

EDIT

Apologies, I wrote earlier that bot "①" and "1" are considered numbers, but they are not. IsNumeric "①" appears as false. Therefore, I think that in general there can be no way to switch from one to the other, except using direct substitution.

Answer 1

fileformat.info tells me that marked numbers can be decomposed into regular numbers. Expressing this in ideone , it is shown that the normalization forms that will ensure that in .NET are KC or KD:

 var one = "①"; Console.WriteLine(one); Console.WriteLine(one.Normalize(NormalizationForm.FormC)); // ① Console.WriteLine(one.Normalize(NormalizationForm.FormD)); // ① Console.WriteLine(one.Normalize(NormalizationForm.FormKC)); // 1 Console.WriteLine(one.Normalize(NormalizationForm.FormKD)); // 1 

However, there is a caution that normalizing the string may also distort other characters that you want to keep as they are.

Answer 2

Well, playing with things, I found that I can convert "①" to this numeric value ( "1" ) using Char.GetNumericValue() , which is pretty interesting because IsNumeric("①") appears as False .

And this also works for “ⅰ” and “Ⅰ” (not letters, but Japanese number format for “1”)

It is a pity that I did not understand the cultural change ...