The first character of my String is printing "?"

Michael Jacquet

12y1.3kVisual Basic .NET

Hello,

I am new to programming and I have a strange issue.

I read lines from a textfile and throw theim separetly in an String Array.

Everything is working fine except that when I WriteLine(Array[0]) it writes in the console:

?My sentence bla bla bla....

All others element of the array write just fine...

Another odd thing is that when I use the imediate window to ask about that element, it writes it just fine.

Here is the code... If someone can figure out my mistake, it would be awesome.

Thank you!

(I didn't find a way to show the code properly so I hope it s readable)

namespace Radio

{

class Program

{

static void Main(string[] args)

{

StreamReader myReader = new StreamReader(@"playlist.txt");

String line = "";

int compteur = 0;

Console.WriteLine("Ordre normal :");

while(line != null)

{

line = myReader.ReadLine();

if(line!=null)

{

Console.WriteLine(line);

compteur++;

}

Console.WriteLine("Nombre de chansons dans la playlist:" + compteur.ToString());

String[] ordreNorm = new string[compteur];

myReader.BaseStream.Position = 0;

for (int i = 0; i < compteur; i++)

{

ordreNorm[i] = myReader.ReadLine();

}

foreach (string song in ordreNorm)

{

Console.WriteLine(song);

}

Console.WriteLine(ordreNorm[0]);

Console.ReadLine();

}

7 Replies

Know the answer? Post it — somebody with the same question will find it here.

Vulpes12y ago
Yes, I think I've figured out now why ANSI works but UTF-8 doesn't.

When notepad creates a file in UTF-8 format, it prepends a 'byte order mark' (BOM) which consists of the 3 bytes EF, BB and BF. This is designed to enable other software to determine the encoding of the file:

http://en.wikipedia.org/wiki/Byte_order_mark

When the StreamReader reads the file it reads the BOM as an actual UTF-8 character unless you use a constructor overload whose second parameter specifies whether the BOM is present or not. The default encoding for StreamReader is UTF8 in any case:

http://msdn.microsoft.com/en-us/library/vstudio/9y86s1a9

This character isn't within a displayable range and so a '?' is printed to the console.

However, when notepad creates a file in ANSI format, there's no BOM and so no additional character is generated by the StreamReader constructor you've used.

One thing I haven't figured out is why the Immediate Window doesn't show this character. May be it's clever enough to realize it's a BOM and so shouldn't be displayed.
Michael Jacquet12y ago
Thank you so much for the interest you put in my issue!
It looks like there is an issue in my text... it's printing:
EF BB BF 6D 75 73 69 71 75

I am now totally lost ^^ I would like to do a print screen.. i m not crazy... That text is starting by "m" from musique 1... I checked and double checked...

Thank you anyway Vulpes!
[EDIT] I found the solution because of your previous answer and checked my txt file.. it was encoded UTF-8 and not ANSI. I changed it to ANSI and It worked...

Thank you very much!
Vulpes12y ago
Try running this code to see what the first nine bytes in the file are:

using System;
using System.IO;

class Test
{
static void Main()
{
string filePath = "playlist.txt";
byte[] bytes = File.ReadAllBytes(filePath);
for(int i = 0; i < 9; i++)
{
Console.Write("{0:X2} ", bytes[i]);
}
Console.ReadKey();
}
}

On my machine, using an ANSI file created in notepad, the output is:

6D 75 73 69 71 75 65 20 31

which are, of course, the hex values of the bytes corresponding to musique 1.
Michael Jacquet12y ago
No, it doesn't work... I tried to write test1 instead and I always got ?test1 It s definetly somthing else... I even tried to past the all code from here to a new project and I goe the same bug...
Vulpes12y ago
I've just run it again with the file contents as above but no '?' is appearing on my machine, so it is a mystery where it's coming from :-/

One thing you could try is deleting the first line of the file and then typing it back in again just in case a non-printing character has somehow got in there.
Michael Jacquet12y ago
Thank you for answering but here is what s inside the txt:
musique 1
musique 2
musique 3
musique 4
musique 5
musique 6

And nothing more! It starts by a m and that "m" is printed (after the ?) And if I change myReader.BaseStream.Position = 0; By myReader.BaseStream.Position = 1;
I get:
??musique 1
musique 2
musique 3....
that s really a weird issue. An idea? Thank you again!
Vulpes12y ago
The '?' appears to be caused by what's in the first line of the file, playlist.txt, as I can't see anything else in the program which would cause it.

My guess is that the first line in the file begins with an accented vowel or some other extended ASCII character greater than 127. The default Console font is unable to show such characters and therefore displays them as an '?' instead.

The immediate window, OTOH, can show them and so they display normally.