## Boolean Expressions

This chapter introduces relational and logical operators. It also discusses the use of these operators to write Boolean expressions.

### 22. Example

Answer:if (  !(cost < 50)  )
System.out.println("Reject these shoes");
else
System.out.println("Acceptable shoes");(There are other ways to write this fragment. See below.)

# Example

It is important to put parentheses around the entire expression so the NOT is applied correctly. Say that you are considering a pair of \$35 shoes. Evaluation proceeds like this:

! ( cost < 50 )! (  35  < 50 )    -----+----             |                  ! (      T    )------+--------      |      F

The entire condition evaluates to false and so the false branch of the if statement is selected. The program prints out "Acceptable shoes".

Question 23:Is the following program fragment correct?if (  !cost < 50  )
System.out.println("Reject these shoes");
else
System.out.println("Acceptable shoes");