CHAPTER 4 (1-30) REVIEW QUESTIONS

Question 1

1. In an if/else if statement, what is the purpose of a trailing else ?

Answer 1

The trailing else provides code that is executed when none of the conditions in the if/else if statement are true.

Question 2

2. Describe the difference between the if/else if statement and a series of if statements.

Answer 2

In an if/else if statement, the conditions are tested until one is found to be true. The conditionally executed statement(s) are executed and the program exits the if/else if statement. In a series of if statements, all of the if statements execute and test their conditions because they are not connected

Question 3

3. What is a flag and how does it work?

Answer 3

A flag is a Boolean variable signaling that some condition exists in the program. When the flag is set to false it indicates the condition does not yet exist. When the flag is set to true it indicates that the condition does exist.

Question 4

4. Can an if statement test expressions other than relational expressions? Explain.

Answer 4

4. Yes. The if statement can test any value that yields a Boolean value (true or false) or a numeric value. When testing a numeric expression, a nonzero numeric value is considered true, and the value 0 is considered false.

Question 5

5. Briefly describe how the && operator works.

Answer 5

5. It takes two expressions as operands and creates a single expression that is true only when both subexpressions are true.

Question 6

6. Briefly describe how the || operator works.

Answer 6

6. It takes two expressions as operands and creates a single expression that is true when either of the subexpressions are true.

Question 7

7. Why are the relational operators called relational?

Answer 7

7. Because they test for specific relationships between items. The relationships are greater-than, less-than, equal-to, greater-than or equal-to, less-than or equal-to, and not equal-to.

Question 8

8. Why do most programmers indent the conditionally executed statements in a decision structure?

Answer 8

8. It visually sets the conditionally-executed statements apart from the surrounding code. This is so you can easily identify the code that is conditionally-executed.

Question 9

9. An expression using the greater-than, less-than, greater-than-or-equal to, less-than-orequal-to, equal, or not-equal to operator is called a(n) __________ expression.

Answer 9

9. relational

Question 10

10. A relational expression is either __________ or __________.

Answer 10

10. true, false

Question 11

11. The value of a relational expression is 0 if the expression is __________ or 1 if the expression is __________.

Answer 11

11. false, true

Question 12

12. The if statement regards an expression with the value 0 as __________.

Answer 12

false

Question 13

13. The if statement regards an expression with a nonzero value as __________.

Answer 13

13. true

Question 14

14. For an if statement to conditionally execute a group of statements, the statements must be enclosed in a set of __________.

Answer 14

braces

Question 15

15. In an if/else statement, the if part executes its statement or block if the expression is __________, and the else part executes its statement or block if the expression is__________.

Answer 15

15. true, false

Question 16

16. The trailing else in an if/else if statement has a similar purpose as the __________ section of a switch statement.

Answer 16

16. default

Question 17

17. The if/else if statement is actually a form of the __________ if statement.

Answer 17

17. nested

Question 18

18. If the sub-expression on the left of the __________ logical operator is false, the right sub-expression is not checked.

Answer 18

18. &&

Question 19

19. If the sub-expression on the left of the __________ logical operator is true, the right sub-expression is not checked.

Answer 19

19. ||

Question 20

20. The __________ logical operator has higher precedence than the other logical operators.

Answer 20

20. !

Question 21

21. The logical operators have __________ associativity.

Answer 21

21. left-to-right

Question 22

22. The __________ logical operator works best when testing a number to determine if it is within a range.

Answer 22

22. &&

Question 23

23. The __________ logical operator works best when testing a number to determine if it is outside a range.

Answer 23

23. ||

Question 24

24. A variable with __________ scope is only visible when the program is executing in the block containing the variable’s definition.

Answer 24

24. block

Question 25

25. You use the __________ operator to determine whether one string object is greater then another string object.

Answer 25

25. >

Question 26

26. An expression using the conditional operator is called a(n) __________ expression.

Answer 26

26. conditional

Question 27

27. The expression that is tested by a switch statement must have a(n) __________ value.

Answer 27

27. integer

Question 28

28. The expression following a case statement must be a(n) __________ __________.

Answer 28

28. integer constant

Question 29

29. A program will “fall through” a case section if it is missing the __________ statement.

Answer 29

29. break

Question 30

30. What value will be stored in the variable t after each of the following statements executes?A) t = (12 > 1); __________B) t = (2 < 0); __________C) t = (5 = = (3 * 2)); __________D) t = (5 = = 5); __________

Answer 30

30. A) 1B) 0 C) 0D) 1