BP CH 4 - Control Statements: pt 2. Logical Operators

Counter-controlled repetition requires a. A control variable and initial value. b. A control variable increment (or decrement). c. A condition that tests for the final value of the control variable. d. All of the above.

ANS: d. All of the above.

Which of the following can be used in a switch statement in the expression after keyword case? A. a constant integral expression. B. a character constant. C. a String D. an enumeration constant. a. A and B. b. A and C. c. B and C. d. All.

ANS: d. All.

Consider the classes below: public class TestA { public static void main(String args[]) { int x = 2; int y = 20 int counter = 0; for (int j = y % x; j < 100; j += (y / x)) counter++; } } public class TestB { public static void main(String args[]) { int counter = 0; for (int j = 10; j > 0; --j) ++counter; } } Which of the following statements is true? a. The value of counter will be different at the end of each for loop for each class. b. The value of j will be the same for each loop for all iterations c. Both (a) and (b) are true. d. Neither (a) nor (b) is true.

ANS: d. Neither (a) nor (b) is true.

Which statement prints the floating-point value 123.456 right justified with a field width of 10? a. System.out.printf("%d10.3", 123.456); b. System.out.printf("%10.3d", 123.456); c. System.out.printf("%f10.3", 123.456); d. System.out.printf("%10.3f", 123.456);

ANS: d. System.out.printf("%10.3f", 123.456);

Which of the following will not help prevent infinite loops? a. Include braces around the statements in a do...while statement. b. Ensure that the header of a for or while statement is not followed by a semicolon. c. If the loop is counter-controlled, the body of the loop should increment or decrement the counter as needed. d. If the loop is sentinel-controlled, ensure that the sentinel value is input eventually.

ANS: a. Include braces around the statements in a do...while statement.

Suppose variable gender contains MALE and age equals 60, how is the expression (gender == FEMALE) && (age >= 65) evaluated? a. The condition (gender == FEMALE) is evaluated first and the evaluation stops immediately. b. The condition (age >= 65) is evaluated first and the evaluation stops immediately. c. Both conditions are evaluated, from left to right. d. Both conditions are evaluated, from right to left.

ANS: a. The condition (gender == FEMALE) is evaluated first and the evaluation stops immediately

The control variable of a counter-controlled loop should be declared as ________to prevent errors. a. int b. float c. double d. Any of the above.

ANS: a. int

boolean values can be displayed as the words true and false with the ________ format specifier. a. %bool. b. %b. c. %true. d. %boolean.

ANS: b. %b.

For the code segment below: switch(q) { case 1: System.out.println("apple"); break; case 2: System.out.println("orange"); break; case 3: System.out.println("banana"); break; case 4: System.out.println("pear"); case 5: System.out.println("grapes"); default: System.out.println("kiwi"); } Which of the following values for q will result in kiwi being included in the output? a. 2. b. Any integer less than 1 and greater than or equal to 4. c. 1. d. 3.

ANS: b. Any integer less than 1 and greater than or equal to 4.

Which of the following for-loop headers results in equivalent numbers of iterations: A. for (int q = 1; q <= 100; q++) B. for (int q = 100; q >= 0; q--) C. for (int q = 99; q > 0; q -= 9) D. for (int q = 990; q > 0; q -= 90) a. A and B. b. C and D. c. A and B have equivalent iterations and C and D have equivalent iterations. d. None of the loops have equivalent iterations.

ANS: b. C and D.

Structured Programming Summary 4.9 Q1: Which statement below is false? a. Structured programming produces programs that are easier to test. b. Structured programming requires four forms of control. c. Structured programming produces programs that are easier to modify d. Structured programming promotes simplicity.

ANS: b. Structured programming requires four forms of control. (Only three forms are necessary: sequence, selection, repetition)

To exit out of a loop completely, and resume the flow of control at the next statement after the loop, use a _______. a. continue statement. b. break statement. c. return statement. d. Any of the above.

ANS: b. break statement.

Logical Operators 4.8 Q1: Consider the code segment below. if (gender == 1) { if (age >= 65) ++seniorFemales; } This segment is equivalent to which of the following? a. if (gender == 1 || age >= 65) ++seniorFemales; b. if (gender == 1 && age >= 65) ++seniorFemales; c. if (gender == 1 AND age >= 65) ++seniorFemales; d. if (gender == 1 OR age >= 65) ++seniorFemales;

ANS: b. if (gender == 1 && age >= 65) ++seniorFemales;

Which expression is equivalent to if (!(grade == sentinelValue))? a. if (grade !== sentinelValue) b. if (grade != sentinelValue) c. ! if (grade == sentinelValue) d. ! if (grade !== sentinelValue)

ANS: b. if (grade != sentinelValue)

Which of the following is equivalent to this code segment? int total = 0; for (int i = 0; i <= 20; i += 2) total += i; a. int total = 0; for (int i = 20; i < 0; i += 1) total += i; b. int total = 0; for (int i = 0; i <= 20; total += i, i += 2); c. int total = 0; for (int i = 0, i <= 20, total += i; i += 2); d. int total = 0; for (int i = 2; i < 20; total += i, i += 2);

ANS: b. int total = 0; for (int i = 0; i <= 20; total += i, i += 2)

The first statement in every paintComponent method should be a call to ________. a. super b. super.paintComponent c. clear d. update

ANS: b. super.paintComponent

Consider the following two Java code segments: Segment 1 Segment 2 int i = 0; for (int i = 0; i <= 20; i++) while (i < 20) { { System.out.println(i); i++; } System.out.println(i); } Which of the following statements are true? a. The output from these segments is not the same. b. The scope of the control variable i is different for the two segments. c. Both (a) and (b) are true. d. Neither (a) nor (b) is true.

ANS: c. Both (a) and (b) are true.

Which case of the following would warrant using the boolean logical inclusive OR (|) rather than the conditional OR (||)? a. Testing if two conditions are both true. b. Testing if at least one of two conditions is true. c. Testing if at least one of two conditions is true when the right operand has a required side effect. d. Testing if at least one of two conditions is true when the left operand has a required side effect.

ANS: c. Testing if at least one of two conditions is true when the right operand has a required side effect

Which of the following statements about a do...while repetition statement is true? a. The body of a do...while loop is executed only if the terminating condition is true. b. The body of a do...while loop is executed only once. c. The body of a do...while loop is always executed at least once. d. None of the above.

ANS: c. The body of a do...while loop is always executed at least once.

Which of the following statements about the break statement is false? a. The break statement is used to exit a repetition structure early and continue execution after the loop. b. A break statement can only break out of an immediately enclosing while, for, do...while or switch statement. c. The break statement, when executed in a while, for or do...while, skips the remaining statements in the loop body and proceeds with the next iteration of the loop. d. Common uses of the break statement are to escape early from a loop or to skip the remainder of a switch. .

ANS: c. The break statement, when executed in a while, for or do...while, skips the remaining statements in the loop body and proceeds with the next iteration of the loop

Which of the following statements about the switch statement is false? a. You can use Strings in a switch statement's controlling expression. b. You can use a String in a switch statement's case label. c. You can use a comma-separated list of Strings in a switch statement's case label. d. You cannot use a String in a switch statement's default case label.

ANS: c. You can use a comma-separated list of Strings in a switch statement's case label.

Which formatting flag indicates that the floating-point values should be output with a thousands separator? a. plus (+). b. minus (-). c. comma (,). d. period (.).

ANS: c. comma (,).

Method drawOval's arguments specify ________. a. the upper-left and upper-right corners of the oval. b. the upper-left corner, scale and size of the oval. c. the position and size of the bounding rectangle for the oval. d. the position and size of the bounding cycle for the oval.

ANS: c. the position and size of the bounding rectangle for the oval.

Which of the following statements about the continue statement is true? a. The continue statement is used to exit a repetition structure early and continue execution after the loop. b. The continue statement is used to continue after a switch statement. c. The continue statement does not alter the flow of control. d. A continue statement proceeds with the next iteration of the immediately enclosing while, for, do...while statement.

ANS: d. A continue statement proceeds with the next iteration of the immediately enclosing while, for, do...while statement.

For the two code segments below: Segment A int q = 5; switch(q) { case 1: System.out.println(1); case 2: System.out.println(2); case 3: System.out.println(3); case 4: System.out.println(4); case 5: System.out.println(5); default: System.out.println("default"); } Segment B q = 4; switch(q) { case 1: System.out.println(1); case 2: System.out.println(2); case 3: System.out.println(3); case 4: System.out.println(4); case 5: System.out.println(5); default: System.out.println("default"); } Which of the following statements is true? a. The output for Segment A is: default b. The output for Segment B is: 4 c. The output for Segment B is: 45default d. The output for Segment A is: 5 default

ANS: d. The output for Segment A is: 5 default

Which of the following will count down from 10 to 1 correctly? a. for (int j = 10; j <= 1; j++) b. for (int j = 1; j <= 10; j++) c. for (int j = 10; j > 1; j--) d. for (int j = 10; j >= 1; j--)

ANS: d. for (int j = 10; j >= 1; j--)

Which of the following is not a type of repetition statement in Java? a. while statement. b. do...while statement. c. for statement. d. loop statement.

ANS: d. loop statement.