如何在 C# 中获取 unicode 字符的十进制值？

Question

How do i get the numeric value of a unicode character in C#?

For example if tamil character அ ( U+0B85 ) given, output should be 2949 (ie 0x0B85 )

See also

• C++: How to get decimal value of a unicode character in c++
• Java: How can I get a Unicode character's code?

Multi code-point characters

Some characters require multiple code points. In this example, UTF-16, each code unit is still in the Basic Multilingual Plane:

• (ie U+0072 U+0327 U+030C )
• (ie U+0072 U+0338 U+0327 U+0316 U+0317 U+0300 U+0301 U+0302 U+0308 U+0360 )

The larger point being that one "character" can require more than 1 UTF-16 code unit, it can require more than 2 UTF-16 code units, it can require more than 3 UTF-16 code units.

The larger point being that one "character" can require dozens of unicode code points. In UTF-16 in C# that means more than 1 char . One character can require 17 char .

My question was about converting char into a UTF-16 encoding value. Even if an entire string of 17 char only represents one "character", i still want to know how to convert each UTF-16 unit into a numeric value.

eg

String s = "அ";

int i = Unicode(s[0]);

Where Unicode returns the integer value, as defined by the Unicode standard, for the first character of the input expression.

Answer 1

It's basically the same as Java. If you've got it as a char , you can just convert to int implicitly:

char c = '\u0b85';

// Implicit conversion: char is basically a 16-bit unsigned integer
int x = c;
Console.WriteLine(x); // Prints 2949

If you've got it as part of a string, just get that single character first:

string text = GetText();
int x = text[2]; // Or whatever...

Note that characters not in the basic multilingual plane will be represented as two UTF-16 code units. There is support in .NET for finding the full Unicode code point, but it's not simple .

Answer 2

((int)'அ').ToString()

If you have the character as a char , you can cast that to an int , which will represent the character's numeric value. You can then print that out in any way you like, just like with any other integer.

If you wanted hexadecimal output instead, you can use:

((int)'அ').ToString("X4")

X is for hexadecimal, 4 is for zero-padding to four characters.

Answer 3

How do i get the numeric value of a unicode character in C#?

A char is not necessarily the whole Unicode code point . In UTF-16 encoded languages such as C#, you may actually need 2 char s to represent a single "logical" character. And your string lengths migh not be what you expect - the MSDN documnetation for String.Length Property says:

"The Length property returns the number of Char objects in this instance, not the number of Unicode characters."

• So, if your Unicode character is encoded in just one char , it is already numeric (essentially an unsigned 16-bit integer). You may want to cast it to some of the integer types, but this won't change the actual bits that were originally present in the char .

• If your Unicode character is 2 char s, you'll need to multiply one by 2^16 and add it to the other, resulting in a uint numeric value:

  char c1 = ...;
  char c2 = ...;
  uint c = ((uint)c1 << 16) | c2;

How do i get the decimal value of a unicode character in C#?

When you say "decimal", this usually means a character string containing only characters that a human being would interpret as decimal digits.

• If you can represent your Unicode character by only one char , you can convert it to decimal string simply by:

  char c = 'அ';
  string s = ((ushort)c).ToString();

• If you have 2 chars for your Unicode character, convert them to a uint as described above, then call uint.ToString .

--- EDIT ---

AFAIK diacritical marks are considered separate "characters" (and separate code points) despite being visually rendered together with the "base" character. Each of these code points taken alone is still at most 2 UTF-16 code units.

BTW I think the proper name for what you are talking about is not "character" but "combining character" . So yes, a single combining character can have more than 1 code point and therefore more than 2 code units. If you want a decimal representation of such as combining character, you can probably do it most easily through BigInteger :

string c = "\x0072\x0338\x0327\x0316\x0317\x0300\x0301\x0302\x0308\x0360";
string s = (new BigInteger(Encoding.Unicode.GetBytes(c))).ToString();

Depending on what order of significance of the code unit "digits" you wish, you may want reverse the c .

Answer 4

This is an example of using Plane 1, the Supplementary Multilingual Plane (SMP):

string single_character = "\U00013000"; //first Egyptian ancient hieroglyph in hex
//it is encoded as 4 bytes (instead of 2)

//get the Unicode index using UTF32 (4 bytes fixed encoding)
Encoding enc = new UTF32Encoding(false, true, true);
byte[] b = enc.GetBytes(single_character);
Int32 code = BitConverter.ToInt32(b, 0); //in decimal

Answer 5

char c = 'அ';
short code = (short)c;
ushort code2 = (ushort)c;