比较C＃中的日文字符

Question

I am checking a Japanese string for spaces and replace them with "_". This is what I am doing:

string input1="abc  dfg";
string input2="尾え　れ";
if(input1.Contains(" "))
{
  Console.WriteLine(input1.Replace(" ","_"));
}
Console.WriteLine("------------------");
if(input2.Contains(" "))
{
  Console.WriteLine(input2.Replace(" ","_"));
}

Here is the Output on this code

abc__dfg
------------------

It replaces spaces with "_" in the simple English string but in the Japanese string it does not.

Answer 1

because the look-like-space in your input2 is not really a space , just check the ascii code of it

Console.WriteLine(Convert.ToInt32('　')); // output: 12288
Console.WriteLine(Convert.ToInt32(' ')); // output: 32

string input1 = "abc  dfg";
string input2 = "尾え　れ"; // a space
string input3 = "尾え れ"; // not a space
if (input1.Contains(" "))
{
    Console.WriteLine(input1.Replace(" ", "_"));
}
Console.WriteLine("------------------");
if (input2.Contains("　"))
{
    Console.WriteLine(input2.Replace("　", "_"));
}
Console.WriteLine("------------------");
if (input3.Contains(" "))
{
    Console.WriteLine(input3.Replace(" ", "_"));
}

---

@Ronan Thibaudau 's original explanation:

Because it's not a space, it's not the same character, copy what you call a "space" from the input 2 string and paste it in the input2.replace method and it will work, it's just not the same character as the space you typed (even when i try to select it here on stackoverflow it's twice as large as the spaces in your input1 so it can't be the same character)

Answer 2

If you don't want to worry yourself with ASCII code or copy-pasting characters you don't know how to expect, just do something like this:

//using System.Linq;
string input1 = "abc  dfg";
string input2 = "尾え　れ";
if (input1.Any(char.IsWhiteSpace))
{

   Console.WriteLine(new string(input1.Select(x=> char.IsWhiteSpace(x) ? '_' : x).ToArray()));
}
Console.WriteLine("------------------");
if (input2.Any(char.IsWhiteSpace))
{

     Console.WriteLine(new string(input2.Select(x => char.IsWhiteSpace(x) ? '_' : x).ToArray()));
}

Answer 3

Most likely your Console font does not support and/or the (default) code page does not support the Japanese characters.

Try

     Console.WriteLine(Console.OutputEncoding.EncodingName);
     Console.WriteLine(Console.OutputEncoding.CodePage);
     Console.WriteLine(input2);
     Debug.Write(input2);

for comparison. Select a font and codepage which supports Japanese characters, eg

Console.OutputEncoding = Encoding.UTF8;

In order to change the default codepage of your Console, please check this answer: Unicode characters in Windows command line - how?

Regarding the string itself: Copy/Paste your string 尾え れ to this side: Unicode code converter . The Unicode codepoints are U+5C3E U+3048 U+3000 U+308C

U+3000 is an Ideographic Space , not the "normal" space U+0020 .

Answer 4

Use this piece of code for the second string and it will work . Tested and it is returning the correct output .

    if (input2.Contains(string.Empty))
    {
        string cleanedString = System.Text.RegularExpressions.Regex.Replace(input2, @"\s+", "_");
        Console.WriteLine(cleanedString);
    }