String Split by Length and split only by nearest space

问题

I am having a Text Like

var data = "âô¢¬ôè÷¢ : ªîø¢è¤ô¢ - ã¿ñ¬ô ñèù¢ ªð¼ñ£÷¢ ï¤ôñ¢,«ñø¢è¤ô¢ - ªð¼ñ£÷¢ ñèù¢ ÝÁºèñ¢ ï¤ôî¢¶è¢°ñ¢ ñ¤ì¢ì£ Üò¢òñ¢ ªð¼ñ£ñ¢ðì¢® è¤ó£ñ âô¢¬ôè¢°ñ¢,õìè¢è¤ô¢ - ÝÁºèñ¢ ï¤ôñ¢,è¤öè¢è¤ô¢ - ôì¢²ñ¤ ï¤ôñ¢ ñø¢Áñ¢ 1,22 ªê ï¤ôñ¢ ð£î¢î¤òñ¢";

and I am Having the Extension Method to split string

public static IEnumerable<string> EnumByLength(this string s, int length)
{
    for (int i = 0; i < s.Length; i += length)
    {
        if (i + length <= s.Length)
        {
            yield return s.Substring(i, length);
        }
        else
        {
            yield return s.Substring(i);
        }
    }
}
public static string[] SplitByLength(this string s, int maxLen)
{
    var v = EnumByLength(s, maxLen);
    if (v == null)
        return new string[] { s };
    else
        return s.EnumByLength(maxLen).ToArray();
}

Now my question is

To split this string by Maximum Length 150 and the splitting must be done only by the Nearest Spaces in it..(either before 150 or after 150.. not in the middle of a word.

How?

回答1:

My version:

// Enumerate by nearest space
// Split String value by closest to length spaces
// e.g. for length = 3 
// "abcd efghihjkl m n p qrstsf" -> "abcd", "efghihjkl", "m n", "p", "qrstsf" 
public static IEnumerable<String> EnumByNearestSpace(this String value, int length) {
  if (String.IsNullOrEmpty(value))
    yield break;

  int bestDelta = int.MaxValue;
  int bestSplit = -1;

  int from = 0;

  for (int i = 0; i < value.Length; ++i) {
    var Ch = value[i];

    if (Ch != ' ')
      continue;

    int size = (i - from);
    int delta = (size - length > 0) ? size - length : length - size;

    if ((bestSplit < 0) || (delta < bestDelta)) {
      bestSplit = i;
      bestDelta = delta;
    }
    else {
      yield return value.Substring(from, bestSplit - from);

      i = bestSplit;

      from = i + 1;
      bestSplit = -1;
      bestDelta = int.MaxValue;
    }
  }

  // String's tail
  if (from < value.Length) {
    if (bestSplit >= 0) {
      if (bestDelta < value.Length - from)
        yield return value.Substring(from, bestSplit - from);

      from = bestSplit + 1;
    }

    if (from < value.Length)
      yield return value.Substring(from);
  }
}

...

var list = data.EnumByNearestSpace(150).ToList();

回答2:

My version

var data = "âô¢¬ôè÷¢ : ªîø¢è¤ô¢ - ã¿ñ¬ô ñèù¢ ªð¼ñ£÷¢ ï¤ôñ¢,«ñø¢è¤ô¢ - ªð¼ñ£÷¢ ñèù¢ ÝÁºèñ¢ ï¤ôî¢¶è¢°ñ¢ ñ¤ì¢ì£ Üò¢òñ¢ ªð¼ñ£ñ¢ðì¢® è¤ó£ñ âô¢¬ôè¢°ñ¢,õìè¢è¤ô¢ - ÝÁºèñ¢ ï¤ôñ¢,è¤öè¢è¤ô¢ - ôì¢²ñ¤ ï¤ôñ¢ ñø¢Áñ¢ 1,22 ªê ï¤ôñ¢ ð£î¢î¤òñ¢";

var indexes = new List<int>();
var lastFoundIndex = 0;
while((lastFoundIndex = data.IndexOf(' ', lastFoundIndex + 1)) != -1)
{
    indexes.Add(lastFoundIndex);
}

int intNum = 150;
int index;
var newList = new List<string>();
while ((index = indexes.Where(x => x > intNum - 150 &&  x <= intNum).LastOrDefault()) != 0)
{
    var firstIndex = newList.Count == 0 ? 0 : index;
    var lastIndex = firstIndex + 150 >= data.Length ? data.Length - 150 : intNum;
    newList.Add(data.Substring(intNum - 150, lastIndex));
    intNum += 150;
}

newList contains the split string

回答3:

There you go:

 for (int i = 0; i < s.Length; i += length)
    {
        int index=s.IndexOf(" ",i, s.Length-i)

        if (index!=-1 && index + length <= s.Length)
        {
            i =index;           
            yield return s.Substring(index, length);
        }
        else
        {
            index= s.LastIndexOf(" ", 0, i);
            if(index==-1)
                yield return s.Substring(i);
            else
            {
                i = index;
                yield return s.Substring(i);
            }
        }
    }

回答4:

Try this, this code will split long sentence into list of lines upto words less than or equal to chunksize :

    private List<string> splitIntoChunks(string toSplit, int chunkSize)
    {
        List<string> splittedLines = new List<string>();

        string [] toSplitAr = toSplit.Split(new char[] { ' ', '\t' }, StringSplitOptions.RemoveEmptyEntries);

        for (int i = 0; i < toSplitAr.Length; )
        {
            string line = "";
            string prefix = "";

            for (int linesize = 0; linesize <= chunkSize;)
            {
                if (i >= toSplitAr.Length) break; //i should not exceed splited array
                prefix = (line == "" ? "" : " "); //prefix with space if not first word in line
                linesize += toSplitAr[i].Length;
                if (linesize > chunkSize) break; //line size should not exceed chunksize
                line += (prefix  + toSplitAr[i]);
                i++;
            }

            splittedLines.Add(line);
        }

        return splittedLines;
    }

来源：https://stackoverflow.com/questions/18396188/string-split-by-length-and-split-only-by-nearest-space

标签

string

linq

ienumerable