Introduction to Java Programming - Building Java Programs: A Back to Basics Approach - page 36

the main method contains fewer lines of code than the DrawBoxes2 program, consider
what would happen if you wanted to add a third box to the output. You would have to
add the five requisite println statements again, whereas in the programs that use the
drawBox method you can simply add one more println and a third method call.
Java allows you to define methods in any order you like. It is a common conven-
tion to put the main method as either the first or last method in the class. In this text-
book we will generally put main first, but the programs would behave the same if we
switched the order. For example, the following modified program behaves identically
to the previous DrawBoxes2 program:
1 public class DrawBoxes3 {
2 public static void drawBox() {
3 System.out.println("+------+");
4 System.out.println("| |");
5 System.out.println("| |");
6 System.out.println("+------+");
7 }
8
9 public static void main(String[] args) {
10 drawBox();
11 System.out.println();
12 drawBox();
13 }
14 }
The main method is always the starting point for program execution, and from that
starting point you can determine the order in which other methods are called.
Methods That Call Other Methods
The main method is not the only place where you can call another method. In fact,
any method may call any other method. As a result, the flow of control can get quite
complicated. Consider, for example, the following rather strange program. We use
nonsense words (“foo,” “bar,” “baz,” and “mumble”) on purpose because the program
is not intended to make sense.
1 public class FooBarBazMumble {
2 public static void main(String[] args) {
3 foo();
4 bar();
5 System.out.println("mumble");
6 }
7
8 public static void foo() {
9 System.out.println("foo");
10 }