why won't this work? i have a txt file that i need to read into a matrix. i want to read into a char array so i can analyze each char separate.

String fname = "c:\\game.txt";
char[][] matrix = new char[4][4];

private void readFile() 
    {
        try
        {
            Scanner s = new Scanner(this.fname);
            char next ;


            for(int i = 0; i < matrix.length; i++)
            {
              for(int j =0; j < matrix.length; j++)
              {        
                    while(s.hasNext() == true)
                    {

                            this.matrix[i][j] = next;

                    }
              }
            } 
        }
        catch(Exception e)
        {
            String s = e.toString();
            System.out.println(s);
        }


    }

I think you would find it easier to read the input into a String and use the charAt() method to read each char in the String.

changed matrix and next to string. now it compiles but when i try running it goes into an endless loop?

Close on the code tags:

[code] // not [/code] here // paste code here

[/code]

Can you post the updated code and an input file?

String data;
String[][] matrix = new String[4][4];


private void readFile() 
    {
        try
        {
            Scanner s = new Scanner(this.fname);
            String next =null;


            for(int i = 0; i < matrix.length; i++)
            {
              for(int j =0; j < matrix.length; j++)
              {        
                    while(s.hasNext() == true)
                    {

                            this.matrix[i][j] = next;

                    }
              }
            } 
        }
        catch(Exception e)
        {
            String s = e.toString();
            System.out.println(s);
        }


    }

Please format and use code tags.

[code]

// paste code here

[/code]

The first tag is [code]

The next is [/code]

There's a slash on the second, but not the first.
I don't know what fname is, but if it's a String and it's a filename and you are reading from a file, you probably want this:

Scanner s = new Scanner(new File (fname));

Next, look at this code:

while(s.hasNext() == true)
{
     this.matrix[i][j] = next;
}

i and j never change, so you are simply overwriting matrix[i][j] continuously. Note that next never changes from null anywhere and you never read the line. You just keep testing s over and over again, but never do anything with it. You probably want something like this:

for (int i = 0; i < matrix.length; i++) 
            {
                for (int j = 0; j < matrix.length; j++) 
                {
                    if (s.hasNext()) 
                    {
                        next = s.nextLine();
                        this.matrix[i][j] = next;
                    }
                    else
                        matrix[i][j] = "no more data";
                }
            }

Note the if instead of the while so you don't keep over-writing matrix[i][j] , and notice that I actually read from the file with s.nextLine () instead of just continually testing it.

class Hb
{


 static char[][] matrix = new char[4][4];
public static void main(String args[])
{
    System.out.println("i am in main");
    System.out.println(matrix.length);
    new Hb().readFile();
    System.out.println(new Hb().matrix[0][0]);
}

private void readFile()
{
try
{

    FileInputStream fi=new FileInputStream("c:/game.txt");
Scanner s = new Scanner(fi);
char next ;


 while(s.hasNext() == true)
 {
     String fname=s.next();
     System.out.println(fname);
for(int i=0,k=0; i < matrix.length && k<fname.length(); i++)
{
for(int j=0; j < matrix.length; j++)
{

if(k<fname.length())
matrix[i][j] = fname.charAt(k++);
System.out.println(matrix[i][j]);
//System.out.println(s.next());
}
System.out.println("hi \n");
}
}

}
catch(Exception e)
{
String s = e.toString();
System.out.println(s);
}

}
}

you can try the above code this will help you on your issue. " Scanner s = new Scanner(this.fname)" this line will read the string which you are passing here fname. to read the file date we need use IO package(i.e.File related classes).

if you find any more please inform

String data;
String[][] matrix = new String[4][4];


private void readFile() 
    {
        try
        {
            Scanner s = new Scanner(this.fname);
            String next =null;


            for(int i = 0; i < matrix.length; i++)
            {
              for(int j =0; j < matrix.length; j++)
              {        
                    while(s.hasNext() == true)
                    {

                            this.matrix[i][j] = next;

                    }
              }
            } 
        }
        catch(Exception e)
        {
            String s = e.toString();
            System.out.println(s);
        }


    }

When you create a Scanner object, you have to do it with an input stream. The name of the file is not an input stream. Do this.

Scanner input = new Scanner(new FileInputStream(fname));