FileInputStream's read() outputs differently when not stored in a variable

Question

Here's my original code:
import java.io.*;
class ShowFile {
     public static void main(String[] args)
     throws IOException{
          FileInputStream fin = new FileInputStream(args[0]);
          int i;
          do {
               i = fin.read();
               if (i != -1) System.out.print((char) fin.read());
          }while (i != -1);
}When i do a "java ShowFile test.txt", it outputs characters that's not the same as the ones in test.txt.
But when I changed the code
if (i != -1) System.out.print((char) fin.read()); to if (i != -1) System.out.print((char) i); everything outputs fine. Why is that?

Answer 1

ajushi wrote:
Thanks laginimaineb.You're welcome.
ajushi wrote:
So when I assign the resulting value from read(), is read() called? Is that the reason why I'm reading 2 chars per loop?Exactly, when you "assign the resulting value from read()" you actually call read, it performs what it needs to, and it returns some value, which you then use.
laginimaineb.