Get the contents of a line in a string

Question

I am using Visual Studio.net, Visual Basic and I have a question. If I have a string that has many lines in it, what is the best way to get the contents of a certain line? Eg If the string is as follows:

Public Property TestProperty1 As String
    Get
        Return _Name
    End Get
    Set(value As String)
        _Name = value
    End Set
End Property

What is the best way to get the contents of line 2 ("Get")?

Answer 1

The simplest is to use ElementAtOrdefault since you don't need to check if the collection has so many items. It would return Nothing then:

Dim lines = text.Split({Environment.NewLine}, StringSplitOptions.None)
Dim secondLine = lines.ElementAtOrDefault(1) ' returns Nothing when there are less than two lines

Note that an index is zero-based, hence i have used ElementAtOrDefault(1) to get the second line.

This is the non-linq approach:

Dim secondLine = If(lines.Length >= 2, lines(1), Nothing) ' returns Nothing when there are less than two lines

Answer 2

That depends on what you mean by "best".

The easiest, but least efficient, is to split the string into lines and get one of them:

Dim second As String = text.Split(Environment.NewLine)(1)

The most efficient would be to locate the line breaks in the string and get the line using Substring , but takes a bit more code:

Dim breakLen As Integer = Environment.Newline.Length;
Dim firstBreak As Integer = text.IndexOf(Environment.Newline);
Dim secondBreak As Integer = text.IndexOf(Environment.NewLine, firstBreak + breakLen)
Dim second As String = text.Substring(firstBreak + breakLen, secondBreak - firstBreak - breakLen)

To get any line, and not just the second, you need even more code to loop through the lines until you get to the right one.