Why does IndexOf() ignore the zero-width non-joiner char, but Replace() doesn't:
class Program
{
static void Main(string[] args)
{
const string zeroWidthNonJoiner = "\u200C";
string str = $"ab{zeroWidthNonJoiner}cd";
int index = str.IndexOf("bc"); //index = 1 (does ignore the zeroWidthNonJoiner)
string replaced = str.Replace("bc", "BC"); //replaced = "abcd" (does NOT ignore the zeroWidthNonJoiner)
}
}
String.Replace(String,string)'s doco doco states:
This method performs an ordinal (case-sensitive and culture-insensitive) search to find oldValue.
String.IndexOf's source code shows that it uses StringComparison.CurrentCulture
public int IndexOf(String value) {
return IndexOf(value, StringComparison.CurrentCulture);
}
In .NET core you can do it with InvariantCulture
string replaced = str.Replace("bc", "BC", StringComparison.InvariantCulture);