storing matrix in a string

[Sharan123]

I want to store a matrix of order N*N in a single string and than print the print the string which will give me display in matrix form(tabular) , this is so
far what i got and it's not in a single but in a array of strings , the code is in c# never mind that.

     public override string ToString()
 {
           string  nothing="\0";
     string[] matrix = new string[s];
     Console.WriteLine("Display");
     for (int i = 0; i < s; i++)
     {
         for (int j = 0; j < s; j++)
         {
            return matrix[i] += (arr1[i, j] + "\t");
             
         }
         Console.WriteLine(matrix[i]);
         
     }
     return nothing;
}