如何确定 String.Split() 中使用的字符

Question

If I am using.Split() how can I find out which character caused the split?

string myMessage = "Apple|Car,Plane-Truck";
//Break apart string
var splits = myMessage.Split(new Char [] {'|', ',', '-'});

foreach (string piece in splits)
{
}

How could I determine which Char ended up being used for the split?

Answer 1

It will split on all of them in the example you've given. but in general, you would just see which of the defined split characters are contained in the string:

var sourceString = "Apple|Car,Plane-Truck";
var allSplitChars = new[] {'|', ',', '-', '.', '!', '?'};

// Find only the characters that are contained in the source string
List<char> charsUsedToSplit = allSplitChars.Where(sourceString.Contains).ToList();

Answer 2

string myMessage = "Apple|Car,Plane-Truck"; //Break apart string var splits = myMessage.Split(new Char[] { '|', ',', '-' }); int accumulated_length = 0; foreach (string piece in splits) { accumulated_length += piece.Length + 1; if (accumulated_length <= myMessage.Length) { Console.WriteLine("{0} was split at {1}", piece, myMessage[accumulated_length - 1]); } else { Console.WriteLine("{0} was the last one", piece); } }

Answer 3

Any characters in the list will be used for the split.. can you clarify what you're actually trying to do? in your example the tokens after the split will be "Apple", "Car", "Plane", "Truck" so each of your characters will be used to split..

If you're trying to determine which character caused the split for each token, then perhaps you might implement the split yourself and keep track:

List<Tuple<String, Char>> Splitter(string msg, char[] chars) {
  var offset = 0;
  var splitChars = new HashSet<char>(chars); 
  var splits = new List<Tuple<String, Char>>();
  for(var idx = 0; idx < msg.Length; idx++) {
    if (splitChars.Contains(msg[idx])) {
      var split = Tuple.Create(msg.Substring(offset, idx - offset), msg[idx]);
      splits.Add(split);
      offset = idx + 1;
    } 
  }
  return splits;
}

string myMessage = "Apple|Car,Plane-Truck";
var splits = Splitter(myMessage, new [] {'|', ',', '-'});
foreach (string piece in splits)
{
    Console.WriteLine("word: {0}, split by: {1}", piece.Item1, piece.Item2);
}