Java Reference
In-Depth Information
Display 4.4
Methods with Parameters
(part 2 of 2)
41
default
:
42
System.out.println("Fatal Error");
43
System.exit(0);
44
return
"Error"; //to keep the compiler happy
45
}
46
}
<
The rest of the method definitions are identical to the ones given in Display 4.2.
>
47
}
This is the file
DateThirdTry.java
.
1
public class
DateThirdTryDemo
2{
3
public static void
main(String[] args)
4
This is the file
DateThirdTryDemo.java
.
{
5
DateThirdTry date =
new
DateThirdTry( );
6
int
year = 1882;
The variable
year
is NOT plugged in for the
parameter
newYear
in the definition of the
method
setDate
. Only the value of
year
,
namely
1882
, is plugged in for the parameter
newYear
.
7
date.setDate(6, 17, year);
8
date.writeOutput( );
9
}
10
}
Sample Dialogue
June 17, 1882
Note that this is exactly the same as the automatic type casting we discussed in
Chapter 1 for storing values of one type in a variable of another type. The more gen-
eral rule is that you can use a value of any of the listed types anywhere that Java expects
a value of a type further down on the list.
Note that the correspondence of the parameters and arguments is determined by
their order in the lists in parentheses. In a method invocation, there must be exactly
the same number of arguments in parentheses as there are formal parameters in the
method definition heading. The first argument in the method invocation is plugged in
for the first parameter in the method definition heading, the second argument in the
method invocation is plugged in for the second parameter in the heading of the
method definition, and so forth. This is diagrammed in Display 4.5.
It is important to note that only the value of the argument is used in this substitution process.
If an argument in a method invocation is a variable (such as
year
in Display 4.4), it is the
