Loops and Logic - Beginning Java - page 94

} else {
System.out.println("It isn\'t Spring!");

}

This calls the equals() method for the enumeration referred to by season . This method compares the
value in season with the value between the parentheses and results in true if they are equal or false if they
are unequal. You could use the equals() method to compare season with another variable of type Season ,
for example:
Season best = Season.winter; // A new variable initialized to winter
if(season.equals(best)) {
System.out.println("season is the same as best, and is equal to "+ best);
} else {
System.out.println(" season has the value "+season +
" and best has the value " + best);

}

After defining the variable, best , you test whether the value of season is the same value as best . If it
is, the first output statement is executed. If best and season are not equal, the output statement in the else
block is executed.

LOGICAL OPERATORS
The tests you have put in the if expressions have been relatively simple so far. Real life is typically more
complicated. You often want to combine a number of conditions so that you execute a particular course —
for example, if they are all true simultaneously. You can ride the roller coaster if you are older than 12 years
old, taller than 4 feet tall, and shorter than 6 feet. Failure on any count and it's no-go. Sometimes, though,
you may need to test for any one of a number of conditions being true — for example, you get a lower price
entry ticket if you are under 16, or over 65.
You can deal with both of these cases, and more, using logical operators to combine several expressions
that have a value true or false . Because they operate on boolean values, they are also referred to as
boolean operators . There are six logical operators that operate on boolean values as shown in Table 3-2 .

TABLE 3-2 : Logical Operators
SYMBOL LONG NAME
&

logical AND

conditional AND &&

logical OR |

conditional OR

||

exclusive OR (XOR) ^

logical negation (NOT) !

The AND and OR operators are very simple; the only point of potential confusion is the fact that you
have the choice of two operators for each of AND and OR. The extra operators are the bitwise & and | from
the previous chapter that you can also apply to boolean values where they have an effect that is subtly dif-
ferent from && and || . Let's first consider what each of these is used for in general terms and then look at
how you can use some of them in an example.