Methods and Formatted Output - Learning Java Through Games - page 62

return type parameters

signature

public static void callBob( ... ){

method name

body

}

FIGURE 4.1: The different parts of a method.

import java . util . ∗ ;
public class Remodel {
public static void main(String [] args) {

callBob() ;
callPeter() ;

}

public static void callBob() {
System. out . println ( "Paint room" );

}

public static void callPeter() {
System. out . println ( "Install hardwood floor" );

}

}

Note that method names should always start with a lowercase letter. The program will
print Paint room followed by Install hardwood floor . Note that one needs to use the
syntax: methodName ( ... ) to call a method. In other words, we always need to use parentheses
when calling a method. The reason is that if we do not use the parentheses, then the compiler
will think that we are referring to the variable callBob and not the callBob method. For
now, all methods will be public and static .A public method means that the method can
be access from everywhere (i.e., a friend that can be called by anyone). A static method
means that the method does not have any hidden parameters. More information on both
keywords will be presented in Chapter 6.
The different parts of a method are shown in Figure 4.1. The parameters of the method
go between the parentheses. This is the information that is sent to the method. In our
example, nothing is sent to both methods. A return type of void means that the method
does not return anything. The first line of the method definition includes the name of the
method, the parameters of the method, and the return type. This line is sometimes referred
to as the signature of the method.
Next, we will show how data can be passed between methods. We will keep the same
example, but now the width and length of the room will be passed to Bob and Peter. Our
friends will paint and put hardwood floor in the room and will send us the bill (they are
our friends, but they will not work for nothing). Here is the modified version of the code.

import java . util . ∗ ;

public class Remodel {
public static void main(String [] args)

{

double bobPrice = callBob(8 , 12) ;
double peterPrice = callPeter (8, 12);