Arrays - Absolute Java - page 382

Display 6.7 Method with a Variable Number of Parameters (part 2 of 2)

1 import java.util.Scanner;

This is the file
VariableParameterDemo.java

2 public class VariableParameterDemo
3 {

4 public static void main(String[] args)
5 {
6 System.out.println("Enter scores for Tom, Dick, and Harriet:");
7 Scanner keyboard = new Scanner(System.in);
8 int tomsScore = keyboard.nextInt();
9 int dicksScore = keyboard.nextInt();
10 int harrietsScore = keyboard.nextInt();

11 int highestScore = UtilityClass.max(tomsScore, dicksScore,
harrietsScore);

12 System.out.println("Highest score = " + highestScore);
13 }
14 }

Sample Dialogue

Enter scores for Tom, Dick, and Harriet:
55 100 99
Highest score = 100

array is done automatically for the programmer. The values for the array are given as
arguments, and Java automatically creates an array and places the arguments in the array.
A parameter specification that specifies any number of parameters, such as int …
arg , is called a vararg specification . (It would make more sense to call it a varparameter
specification, but the word vararg is too well entrenched, so we will go along with
common usage.) The three dots in a vararg specification are called an ellipsis . Note
that the ellipsis is part of the Java syntax and not an abbreviation used in this topic.
You type in the three dots.
You can have only one variable parameter specification, such as int … arg , in a method
definition. However, you may also have any number of ordinary parameters, in which case
the vararg specification must be the last item on the parameter list. This is illustrated in
Display 6.8, which we discuss in the next subsection.
In Chapter 2, you saw one example of a method that accepts a variable number of
arguments, namely the method System.out.printf . However, we could not tell you
how to define such methods yourself until we covered the basics about arrays.

vararg
specification

ellipsis