Methods ?customer example

Continuing with the Customer example: suppose we need the program to be able to print each customer's account balance on the screen (perhaps using System.out.println() or Graphics.drawString() ). A sensible place to put the instructions for this is in a method called `printBalance' (for example). We might define this method like this:

class Customer
{
  String name;
  String address;
  int accountBalance;
  int creditLimit;

  // printBalance method
  // prints the customer's balance

   public void printBalance ()
   {
      System.out.println 
              ("Current balance for " 
               + name 
               + " is " 
               + accountBalance
               + " pounds");
   }
}

Current balance for Fred Bloggs is 2000 pounds

public void printBalance ()

The keyword `void' means that this method has no return value ('output'). The empty parentheses (brackets) mean that the method has no arguments ('inputs'). 

It is often pointed the printBalance does have a form of output: it produces an output on the screen. This confusion is the reason why we tend to use the term 'return value' here rather that 'output'. When it is said that printBalance has no return value, what is meant is that it would be meaningless to write a line like:

x = printBalance();