CONTROL STRUCTURES I: SELECTION - Java Programming: From Problem Analysis to Program Design - page 184

TABLE 4-5 ! (not) Operator

Expression !(Expression)

true false

false true

EXAMPLE 4-1

Expression Value Explanation

!('A' > 'B') true

Because 'A' > 'B' is false , !('A' > 'B') is true .

false Because 6 <= 7 is true , !(6 <= 7) is false .

!(6 <= 7)

Table 4-6 defines the operator && (and). From this table, it follows that Expression1 &&
Expression2 is true if and only if both Expression1 and Expression2 are true ;
otherwise, Expression1 && Expression2 evaluates to false . Table 4-6 is called the
truth table of the operator && . Example 4-2 gives examples of the && operator.

TABLE 4-6 && (and) Operator

Expression1 Expression2 Expression1 && Expression2

true true true

true false false

false true false

false false false

EXAMPLE 4-2

Expression Value Explanation

(14 >= 5) && ('A' < 'B') true

Because (14 >= 5) is true , ('A' < 'B')
is true , and true && true is true , the
expression evaluates to true .

(24 >= 35) && ('A' < 'B') false

Because (24 >= 35) is false , ('A' < 'B')
is true ,and false && true is false ,the
expression evaluates to false .