What method in the String class returns only the f

Question

I'd like to write an extension method to the String class so that if the input string to is longer than the provided length N, only the first N characters are to be displayed.

Here's how it looks like:

public static string TruncateLongString(this string str, int maxLength)
{
    if (str.Length <= maxLength)
        return str;
    else
        //return the first maxLength characters                
}

What String.*() method can I use to get only the first N characters of str?

Answer 1

You can use LINQ str.Take(n) or str.SubString(0, n), where the latter will throw an ArgumentOutOfRangeException exception for n > str.Length.

Mind that the LINQ version returns a IEnumerable<char>, so you'd have to convert the IEnumerable<char> to string: new string(s.Take(n).ToArray()).

Answer 2

string.Substring(0,n); // 0 - start index and n - number of characters

Answer 3

substring(int startpos, int lenght);

Answer 4

public static string TruncateLongString(this string str, int maxLength)
{
    if (string.IsNullOrEmpty(str))
        return str;
    return str.Substring(0, Math.Min(str.Length, maxLength));
}

Answer 5

string truncatedToNLength = new string(s.Take(n).ToArray());  

This solution has a tiny bonus in that if n is greater than s.Length, it still does the right thing.