char and throws java.io.IOException

Hi.
Is throws java.io.IOException can be used together with char only?
How about int, String, long... ...
for example,

class ReadChar {
public static void print( long num )
throws java.io.IOException{

System.out.println( "Type a number and press [Enter]" );
num = (long)System.in.read();
System.out.println( "You typed " + num );
}
}

In this case, when I type 7, it stated I typed 55.
Why? Hope to get the answer soon.
Thank you.

This has nothing to do with IOException and all to do with wrong code. You don't read in input this way. System.in is an InputStream and calling read() reads a byte from the Stream as a byte, not as a character in a String.

Instead you should use either a BufferedInputStream:

Code:

---

BufferedReader in
  = new BufferedReader(new InputStreamReader(System.in));

---

or a Scanner object:

Code:

---

Scanner scan = new Scanner(System.in);

---

Just an FYI - It said you typed 55 because you did. In Ascii. The character for the number 7 is at index 55 on the ASCII Chart. Do what fubarable said and you shouldn't have this problem.

thank you:)