File.ReadAllLines() vs StreamReader
Posted by fr3dr1k | Filed under Application Development, C#
A couple of days ago I forced myself to memorize the C# code for reading from a file (text, html), and for it I used the StreamReader class (on MSDN):
try
{
using(StreamReader reader = new StreamReader('filename'))
{
string s;
while((s = reader.ReadLine()) != null)
{
Console.WriteLine(s);
}
}
}
catch(Exception ex)
{
Console.WriteLine(ex.Message);
}
This is in comparison to the File class which has a method called ReadAllLines, and its biggest benefit is that it results in less code. Is less more? I’m not sure yet. With the StreamReader class you can create a method that implements IEnumerable which allows you to use the foreach on it. I found the sample for this on http://stackoverflow.com/questions/286533/filestream-streamreader-problem-in-c.
public static IEnumerableReadLines(string path) { using (StreamReader reader = File.OpenText(path)) { string line; while ((line = reader.ReadLine()) != null) { yield return line; } } } foreach(string line in ReadLines(file)) { Console.WriteLine(line); }
It is also mentioned that the StreamReader approach works nicely with Linq. Another thing that was mentioned is that the StreamReader uses a concept called lazy evaluation and this increases performance.
Does the less code option result in better performance just because it uses less lines of code? I’m a bit undecided. Maybe I will have a better opinion in the future.
