More Conditionals and Loops - Java Software Solutions: Foundations of Program Design - page 275

Let's look at a couple more examples. Consider the following declaration:

int larger = (num1 > num2) ? num1 : num2;

If num1 is greater than num2 , the value of num1 is returned and used to ini-
tialize the variable larger . If not, the value of num2 is returned and used to
initialize larger . Similarly, the following statement prints the smaller of the
two values:

System.out.println ("Smaller: " + ((num1 < num2) ? num1 : num2));

The conditional operator is occasionally helpful to evaluate a short condi-
tion and return a result. It is not a replacement for an if-else statement, how-
ever, because the operands to the ?: operator are expressions, not necessarily
full statements. Even when the conditional operator is a viable alternative,
you should use it carefully because it may be less readable than an if-else
statement.

SELF-REVIEW QUESTIONS (see answers in Appendix N)
SR 6.5 What is the difference between a conditional operator and a condi-

tional statement?

SR 6.6 Write a declaration that initializes a char variable named id to 'A' if

the boolean variable first is true and to 'B' otherwise.

SR 6.7 Express the following logic in a succinct manner using the conditional

operator.

if (val <= 10)
System.out.println ("The value is not greater than 10.");
else
System.out.println ("The value is greater than 10.");

6.3 The do Statement

Remember from Chapter 5 that the while statement first examines its condi-
tion, then executes its body if that condition is true. The do statement is similar
to the while statement except that its termination condition is at the end of
the loop body. Like the while loop, the do loop executes the statement in the
loop body until the condition becomes false. The condition is written at the end
of the loop to indicate that it is not evaluated until the loop body is executed.
Note that the body of a do loop is always executed at least once. Figure 6.1
shows this processing.