Cut the string to be <= 80 characters AND must keep the words without cutting them

Question

I am new to C#, but I have a requirement to cut the strings to be <= 80 characters AND they must keep the words integrity (without cutting them)

Examples

Answer 1

Here's an approach without using Regex: just split the string (however you'd like) into whatever you consider "words" to be. Then, just start concatenating them together using a StringBuilder, checking for your desired length, until you can't add the next "word". Then, just return the string that you have built up so far.

(Untested code ahead)

public string TruncateWithPreservation(string s, int len)
{
    string[] parts = s.Split(' ');
    StringBuilder sb = new StringBuilder();

    foreach (string part in parts)
    {
        if (sb.Length + part.Length > len)
            break;

        sb.Append(' ');
        sb.Append(part);
    }

    return sb.ToString();
}