CONTROL STRUCTURES I: SELECTION - Java Programming: From Problem Analysis to Program Design - page 187

the operator || evaluates before the operator && ; whereas, in the expression:
7 >= 8 || 'A' < 'B' && 5 * 4 == 20
the operator && evaluates before the operator || .
Example 4-5 illustrates how logical expressions consisting of variables are evaluated.

EXAMPLE 4-5

Suppose you have the following declarations:

4

boolean found = true ;
double hours = 45.30;
double overTime = 15.00;
int count = 20;
char ch = 'B';
Consider the following expressions:

Expression Value / Explanation

!found false

Because found is true , !found is false .

hours > 40.00 true

Because hours is 45.30 and 45.30 > 40.00 is
true , the expression hours > 40.00 evaluates to
true .

!found && (hours >= 0) false

!found is false ; hours >= 0 is 45.30 >= 0 is
true . Therefore,!found && (hours >= 0) is
false && true , which evaluates to false .

!(found && (hours >= 0)) false

Now, found && (hours >= 0) is true && true ,
which evaluates to true .Therefore,!(found &&
(hours >= 0)) is ! true , which evaluates to false .

hours + overTime <= 75.00 true

Because hours + overTime is 45.30 + 15.00
= 60.30 and 60.30 <= 75.00 is true , it follows
that hours + overTime <= 75.00 evaluates to
true .

(count >= 0) &&
(count <= 100)

true
Now count is 20. Because 20 >= 0 is true ,
count >= 0 is true . Also, 20 <= 100 is true ,
so count <= 100 is true . Therefore,
(count >= 0) && (count <= 100) is true
&& true , which evaluates to true .

('A' <= ch && ch <= 'Z') true

Here, ch is 'B'. Because 'A' <= 'B' is true ,
'A' <= ch evaluates to true . Also, because 'B'
<= 'Z' is true , ch <= 'Z' evaluates to true .
Therefore, ('A' <= ch && ch <= 'Z') is true
&& true , which evaluates to true .