Find duplicate characters in a string using c#
public class StringDataStructure
{
//Find the duplicate character
public StringBuilder GetDuplicateCharacter(string _title)
{
StringBuilder result = new StringBuilder();
StringBuilder duplicateChar = new StringBuilder();
foreach (var item in _title)
{
if (result.ToString().IndexOf(item.ToString().ToLower()) == -1)
{
result.Append(item);
}
else
{
duplicateChar.Append(item);
}
}
return duplicateChar;
}
}