How to split string preserving whole words?

Question

I need to split long sentence into parts preserving whole words. Each part should have given maximum number of characters (including space, dots etc.). For example:

int partLenght = 35;
string sentence = "Silver badges are awarded for longer term goals. Silver badges are uncommon."

Output:

1 part: "Silver badges are awarded for"
2 part: "longer term goals. Silver badges are"
3 part: "uncommon."

Answer 1

At first I was thinking this might be a Regex kind of thing but here's my shot at it:

List<string> parts = new List<string>();
int partLength = 35;
string sentence = "Silver badges are awarded for longer term goals. Silver badges are uncommon.";

string[] pieces = sentence.Split(' ');
StringBuilder tempString = new StringBuilder("");

foreach(var piece in pieces)
{
    if(piece.Length + tempString.Length + 1 > partLength) 
    {
        parts.Add(tempString.ToString());
        tempString.Clear();        
    }
    tempString.Append(" " + piece); 
}

Answer 2

Joel there is a little bug in your code that I've corrected here:

public static string[] StringSplitWrap(string sentence, int MaxLength)
{
        List<string> parts = new List<string>();
        string sentence = "Silver badges are awarded for longer term goals. Silver badges are uncommon.";

        string[] pieces = sentence.Split(' ');
        StringBuilder tempString = new StringBuilder("");

        foreach (var piece in pieces)
        {
            if (piece.Length + tempString.Length + 1 > MaxLength)
            {
                parts.Add(tempString.ToString());
                tempString.Clear();
            }
            tempString.Append((tempString.Length == 0 ? "" : " ") + piece);
        }

        if (tempString.Length>0)
            parts.Add(tempString.ToString());

        return parts.ToArray();
}

Answer 3

Try this:

    static void Main(string[] args)
    {
        int partLength = 35;
        string sentence = "Silver badges are awarded for longer term goals. Silver badges are uncommon.";
        string[] words = sentence.Split(' ');
        var parts = new Dictionary<int, string>();
        string part = string.Empty;
        int partCounter = 0;
        foreach (var word in words)
        {
            if (part.Length + word.Length < partLength)
            {
                part += string.IsNullOrEmpty(part) ? word : " " + word;
            }
            else
            {
                parts.Add(partCounter, part);
                part = word;
                partCounter++;
            }
        }
        parts.Add(partCounter, part);
        foreach (var item in parts)
        {
            Console.WriteLine("Part {0} (length = {2}): {1}", item.Key, item.Value, item.Value.Length);
        }
        Console.ReadLine();
    }