How to retrieve a StringBuilder Line Count?

Question

I have a StringBuilder instance where I am doing numerous sb.AppendLine("test"); for example.

How do I work out how many lines I have?

I see the class has .Length but that tells me how many characters in all.

Any ideas?

Answer 1

You should be able to search for the number of occurences of \n in the string.

UPDATE: One way could be to split on the newline character and count the number of elements in the array as follows:

sb.ToString().Split('\n').length;

Answer 2

You could wrap StringBuilder with your own class that would keep a count of lines as they are added or could the number of '\n' after your builder is full.

Regex.Match(builder.ToString(), Environment.NewLine).Length

Answer 3

Do a regex to count the number of line terminators (ex: \r\n) in the string. Or, load the strings into a text box and do a line count but thats the hack-ey way of doing it

Answer 4

Try this:

sb.ToString().Split(System.Environment.NewLine.ToCharArray()).Length;

Answer 5

You can split string bulider data into String[] array and then use String[].Length for number of lines.

something like as below:

String[] linestext = sb.Split(newline)
Console.Writeline(linetext.Length)

Answer 6

Derive your own line counting StringBuilder where AppendLine ups an internal line count and provides a method to get the value of line count.

Answer 7

You can create a wrapper class do the following:

public class Wrapper
{
    private StringBuilder strBuild = null;
    private int count = 0;
    public Wrapper(){
        strBuild = new StringBuilder();
    }
    public void AppendLine(String toAppendParam){
        strBuild.AppendLine(toAppendParam);
        count++;
    }
    public StringBuilder getStringBuilder(){
        return strBuild;
    }

    public int getCount(){
        return count;
    }
}

Answer 8

Sorted by efficiency:

1. Counting your AppendLine() calls
2. Calling IndexOf() in a loop
3. Using Regex
4. Using String.Split()

The last one is extraordinary expensive and generates lots of garbage, don't use.

Answer 9

If you're going to use String.Split(), you will need to split the string with some options. Like this:

static void Main(string[] args)
{
    var sb = new StringBuilder();
    sb.AppendLine("this");
    sb.AppendLine("is");
    sb.AppendLine("test");

    // StringSplitOptions.None counts the last (blank) newline 
    // which the last AppendLine call creates
    // if you don't want this, then replace with 
    // StringSplitOptions.RemoveEmptyEntries
    var lines = sb.ToString().Split(
        new string[] { 
            System.Environment.NewLine }, 
        StringSplitOptions.None).Length;

    Console.WriteLine("Number of lines: " + lines);

    Console.WriteLine("Press enter to exit.");
    Console.ReadLine();
}

This results in:

Number of lines: 4