Java Reference
In-Depth Information
(year == otherDate.year && getMonth() < otherDate.getMonth())
||
(year == otherDate.year && month.equals(otherDate.month)
&& day < otherDate.day) );
}
The version of our date class with this method is given in Display 4.7. The other new
methods in that class will be discussed shortly in the subsection entitled “The Methods
equals
and
toString
.” Right now, let's discuss this new method named
precedes
.
An invocation of the method
precedes
has the following form, where
date1
and
date2
are two objects of our date class:
date1.precedes(date2)
This is a Boolean expression that returns
true
if
date1
comes before
date2
. Because it
is a Boolean expression, it can be used anyplace a Boolean expression is allowed, such as
to control an
if-else
or
while
statement. For example,
if
(date1.precedes(date2))
System.out.println("date1 comes before date2.");
else
System.out.println("date2 comes before or is equal to date1.");
Display 4.7
A Class with Methods
equals
and
toString
(part 1 of 2)
1
import
java.util.Scanner;
2
public class
DateFourthTry
3{
4
private
String month;
5
private int
day;
6
private int
year;
//a four digit number.
7
public
String toString()
8
{
9
return
(month + " " + day + ", " + year);
10
}
11
public void
writeOutput()
12
{
13
System.out.println(month + " " + day + ", " + year);
This is the method
equals
in the
class
DateFourthTry.
This is the method
equals
in the class
String.
14
}
15
public boolean
equals(DateFourthTry otherDate)
16 {
17
return
( (month.equals(otherDate.month))
18 && (day == otherDate.day) && (year == otherDate.year) );
19
}
(continued)
