The output problem of integer numbers

  • Suppose you have a byte variable x and it contains the 2s complement code 00000011 (= value 3(10) (i.e.: 48 dots))

    When we print x, we want to see: 

          3

  • If we send 00000011 to the terminal, it will print a strange symbol !!!

    (Because 00000011 is an unprintable ASCII code for "End of Message")

  • In order to print the number 3 on a terminal, we must send this ASCII code to the terminal: 

         00110011    (= the ASCII code for the character 3)

The output problem of integer numbers - explained graphically

If we "print" (= send) the 2s complement code 00000011 (= 3(10)) directly to the terminal:                                    

 

The terminal will not display the decimal number 3.

The output problem of integer numbers - explained graphically

In order to print a 2s compl code in the decimal sign-magnitude representation to the user, we must first convert to a number string:

 

And then print (= send) the ASCII code(s) in the number string to the terminal.

Java library method that performs the int --> String conversion
 

The toString( ) method in the Integer class:

 

In the next few webpages, I will show you what is going on inside the toString( ) method