Replace German characters (umlauts, accents) with english equivalents

Question

Replace German characters (umlauts, accents) with english equivalents

I need to remove any german specific characters from various fields of text for processing into another system which wont accept them as valid.

So the characters I am aware of are:

ß ä ö ü Ä Ö Ü

At the moment I have a bit of a manual way of replacing them:

myGermanString.Replace("ä","a").Replace("ö","o").Replace("ü","u").....

But I was hoping there was a simpler / more efficient way of doing it. Since I'll be doing it on thousands of strings per run, 99% of which will not contain these chars.

Maybe a method involving some sort of CultureInfo?

(for example, according to MS, the following returns the strings are equal

String.Compare("Straße", "Strasse", StringComparison.CurrentCulture);

so there must be some sort of conversion table already existing?)

Solution

The process is known as removing "diacritics" - see Removing diacritics (accents) from strings which uses the following code:

public static String RemoveDiacritics(String s)
{
  String normalizedString = s.Normalize(NormalizationForm.FormD);
  StringBuilder stringBuilder = new StringBuilder();

  for (int i = 0; i < normalizedString.Length; i++)
  {
    Char c = normalizedString[i];
    if (CharUnicodeInfo.GetUnicodeCategory(c) != UnicodeCategory.NonSpacingMark)
      stringBuilder.Append(c);
  }

  return stringBuilder.ToString();
}

Comments

[ChrisF]

Can you summarise the post here. It helps to keep the information in one place and helps guard against link rot.

[jb.]

What this doesnt work for is the 'ß' character - which is just returned as it was.

[Alex Essilfie]

@jb. I believe you'll have to do a hard replace of the German characters in order to achieve the desired effect. This may be the preferable method since one-character German letters with umlauts can be mapped to two-character non-umlaut versions. See the answers to the question linked in Joe's answer for solutions.