Chapter 4

4.1. Which is not a repetition structure? a) continue b) for c) while d) do ... while

A

4.20. Which statement is false? a) Comma operators evaluate lists of expressions from right to left. b) The value of a comma-separated list of expressions is the value of the rightmost expression in the list. c) The type of a comma-separated list of expressions is the type of the rightmost expression in the list. d) The comma operator is often used to specify multiple initializations in one particular type of repetition structure.

A

4.3 ________ repetition is sometimes called definite repetition. (a) counter-controlled (b) sentinel-controlled (c) variable-controlled (d) none of these

A

4.34. Which statement is generally false? a) Statements preceding a for and statements in the body of a for should typically be merged into the for header. b) Limit the size of control structure headers to a single line, if possible. c) Initialization of a for loop control variable can occur before the for loop executes and not in the loop itself. d) The increment portion of a for header can be a decrement.

A

4.54 Variables are also known as (a) lvalues, but can be used as rvalues (b) lvalues, and can not be used as rvalues (c) rvalues, but can be used as lvalues (d) constant variables

A

4.55 Consider the following code, assuming that x is an integer variable with an initial value of 12: if( x = 6 ) printf("%i", x); What is the output? (a) 6 (b) 12 (c) nothing (d) a syntax error is produced

A

4.12. Which data type should normally not be used to control a counting loop? a) int b) float c) short d) long

B

4.23. A program contains a for-loop with the following for header: for(counter = 1; ; counter++) The programmer's intent was most likely to create a) a syntax error b) an infinite loop c) a logic error d) a divide-by-zero error

B

4.27. Which statement regarding for statements is false? a) In a for statement, the initialization, loop-continuation condition, and increment can contain arithmetic expressions. b) The increment must be greater than zero. c) If the loop-continuation condition is initially false, the body of the loop is not performed. d) It is common to use the control variable for controlling repetition while never mentioning it in the body of the loop.

B

4.31. The for statement header for ( i = 1; i < 100; i++ ) performs the body of the loop for a) values of the control variable from 1 to 100 in increments of 1. b) values of the control variable from 1 to 99 in increments of 1. c) values of the control variable from 0 to 100 in increments of 1. d) values of the control variable from 0 to 99 in increments of 1.

B

4.32. What is the highest value assumed by the loop counter in a correct for statement with the following header? for ( i = 7; i <= 72; i += 7) a) 7 b) 77 c) 70 d) 72

B

4.39 In a switch statement (a) a break is required after each case (b) multiple actions do not need to be enclosed in braces (c) a default case is required (d) a break is required after the default case

B

4.4 ________ repetition is sometimes called indefinite repetition. (a) counter-controlled (b) sentinel-controlled (c) variable-controlled (d) none of these

B

4.40. Which statement regarding the switch statement is false? a) It is appropriate for algorithms that contain a series of decisions in which a variable or expression is tested separately for each of the constant integral values it may assume. b) The default case is required. c) The default case must be at the bottom of the switch after all the non-default cases. d) Many cases may all invoke the same code.

B

4.43 The following program segment will int counter = 1; do { printf( "%i ", counter ); } while ( ++counter <= 10 ) ; (a) print the numbers 1 through 11 (b) print the numbers 1 through 10 (c) print the numbers 1 through 9 (d) cause a syntax error

B

4.47 In C, the condition 4 > y > 1 (a) evaluates correctly (b) does not evaluate correctly and should be replaced by ( 4 > y && y > 1 ) (c) does not evaluate correctly and should be replaced by ( 4 > y & y > 1 ) (d) does not evaluate correctly and should be replaced by ( 4 > y || y > 1 )

B

4.48 The OR (||) operator (a) has higher precedence than the AND (&&) operator (b) stops evaluation upon finding one condition to be true (c) associates from right to left (d) is a ternary operator

B

4.58 The ____________, __________, and ____________ are the only three forms of control necessary. (a) switch, if, else (b) sequence, selection, repetition (c) break, continue, if...else (d) for, while, do...while

B

4.8 The statement while ( -- counter >= 1 ) printf( "%s\n", counter % 2 ? "even" : "odd" ); can not be rewritten as (a) while ( -- counter >= 1 ) if ( counter % 2 ) printf( "even" ); else printf( "odd" ); (b) while ( counter >= 1 ) if (counter % 2) printf( "even" ); else printf( "odd" ); --counter; (c) while ( counter >= 1 ) { if ( counter % 2 ) printf( "even" ); else printf( "odd" ); --counter; } (d) do { printf( "%s\n", counter % 2 ? "odd" : "even" ); --counter; }while ( counter >= 2 );

B

4.9 Which of the following is a bad programming practice? (a) indenting the statements in the body of each control structure (b) using floating-point values as the counter in counter-controlled repetition (c) using more than two levels of nesting (d) placing vertical spacing above and below control structures

B

4.10. Which is not always required by counter-controlled repetition? a) The name of a control variable (or loop counter). b) The initial value of the control variable. c) The decrement by which the control variable is modified each time through the loop. d) The condition that tests for the final value of the control variable (i.e., whether looping should continue.

C

4.11. In the context of counter-controlled repetition, which of the following is not accomplished by the control-variable initialization statement? int c = 10; a) Names the control variable. b) Defines the control variable to be an integer. c) Specifies the sentinel value. d) Sets the initial value of the control variable to 10.

C

4.14 Which of the following is not true?(a) the three expressions in the for statement are optional. (b) the initialization and increment expressions can be comma-seperated lists. (c) you must define the control variable outside of the for loop. (d) All of the above are true.

C

4.18. Using an incorrect relational operator or using an incorrect final value of a loop counter in the condition of a while or for statement is a frequent cause of __________errors. a) syntax b) compilation c) off-by-one d) divide-by-zero

C

4.19. The comma operator is most often used in __________ statements. a) while b) do ... while c) for d) switch

C

4.2.Which statement is used to skip the remainder of the body of a repetition struction and proceed with the next iteration of the loop? a) skip b) proceed c) continue d) jump

C

4.22. Omitting the expression before the first required semi-colon in a for "header" is likely to cause a(n) __________ error. a) syntax b) infinite loop c) logic d) divide-by-zero

C

4.25 If the loop-continuation condition is initially false, ________. (a) the body portion of the loop is not performed (b) execution proceeds with the statement following the for statement (c) both a and b (d) none of the above

C

4.28. Which statement about a correct for statement with an initialization expression, a loop-continuation test, an increment expression and a loop body is false? a) The incrementing is performed each time through the loop. b) The loop-continuation test is evaluated each time through the loop. c) The initialization is performed each time through the loop. d) The increment expression is performed after the loop body.

C

4.29 Which of the following for headers is not valid? (a) int i; for( i = 0; i < 10; i++ ) (b) int i = 0; for( ; i < 10; i++ ) (c) int i; for( ; ; i++) (d) int i = 0; for( ; i < 10; )

C

4.33. What is produced by a for statement with a correct body and with the following header for ( i = 20; i >= 2; i += 2 ) a) a syntax error b) a divide-by-zero error c) an infinite loop d) the even values of i from 20 down to 2.

C

4.36. Which statement is true? a) Use float variables to perform monetary calculations in C. b) Use double variables to perform monetary calculations C. c) Monetary calculations can be performed in C. d) Printing with %.2f guarantees correct monetary calculations in C.

C

4.38 A switch statement should be used (a) as a single-selection structure (b) as a double-selection structure (c) when a variable may assume many different values which must be tested against (d) to replace all if and if...else statements

C

4.42 If a do...while statement is used, (a) an infinite loop will not take place (b) the counter must be preincremented if it is also the condition (c) the body of the loop will execute at least once (d) an off-by-one error will not occur

C

4.44. Which statement is true? a) The do ... while repetition statement is an alternate notation for the while repetition statement; these statements function identically. b) The do ... while repetition statement tests the loop-continuation condition before the loop body is performed. c) The loop body of a correct do ... while repetition statement is always executed at least once. d) The braces delineating the body of a do ... while statement are always required.

C

4.51 An example of a unary operator is (a) a relational operator (b) an assignment operator (c) an increment operator (d) a logical operator

C

4.52. Which statement is true? a) To test multiple conditions in the process of making a decision requires logical operators. b) The keywords for the logical operators are AND, OR and NOT. c) The logical AND of two expressions is true if and only if each of the conditions is true. d) Truth tables deal only with cases in which all conditions are truthful (i.e., true).

C

4.57. Which statement is false? a) Any expression in C that produces a value can be used in the decision portion of any control structure. b) When tested for truth or falsity, an expression that produces a nonzero value is treated as true. c) Assignments in C produce a value, namely the value that the left-hand side of the assignment had prior to the assignment. d) Operator == is for comparisons; operator = is for assignment.

C

4.59. Which statement is true? a) Connecting flowchart symbols arbitrarily always forms structured programs. b) In a structured program, control structures can be only stacked or sequenced. c) In the "Rules for Forming Structured Programs (and Structured Flowcharts)," the rule that states, "Any rectangle (action) can be replaced by any control structure" is called the "nesting rule." d) Any form of control ever needed in a C program can be expressed in terms of the while, do ... while and for statements.

C

4.6. Which statement is true? a) Sentinel values are used to control repetition when the precise number of repetitions is known in advance. b) Sentinel values are used to control repetition when the loop does not include statements that obtain data each time the loop is performed. c) Sentinels must be distinct from regular data items. d) Sentinel-controlled repetition is often called definite repetition.

C

4.13. Which statement is generally false? a) Control counting loops with integer values. b) Indent the statements in the body of each control structure for clarity. c) Put a blank line before and after each major control structure to make it stand out in the program. d) The more deeply nested a program is, the easier it is to understand.

D

4.16. Which of the following is not specified by the following correct code segment: for ( c = 1; c <= 10; c++ ) a) initial value of the loop counter b) loop continuation test c) increment of the loop counter d) body statement of the loop

D

4.17. A programmer writes a for statement to count from 1 to 10 and explicitly mentions the 1 and the 10 in the for "header." Which relational operator would probably be used in the loop-continuation test? a) > b) >= c) < d) <=

D

4.21. What happens if the loop-continuation test is omitted in a for-statement? a) C assumes the condition is false, so the loop terminates. b) A syntax error occurs. c) C assumes the condition is true, so the loop executes one more time, then terminates. d) An infinite loop.

D

4.24. Which of the following is an incorrect expression to increment c by 1 in the increment expression of a for "header?" a) c += 1 b) ++c c) c++ d) c + 1 = c

D

4.26 If the increment of the for statement is ________ then the loop counts ________. (a) true, downwards (b) false, downwards (c) positive, downwards (d) negative, downwards

D

4.35. Which expression raises x to the y power a) x ** y b) x ^ y c) x pow y d) pow( x, y )

D

4.37. Which statement is true? a) The conversion specifier %7.2f prints a floating-point value with a field width of 10 positions. b) The conversion specifier %7.2f prints a floating-point value with 7 positions to the left of the decimal point. c) The conversion specifier %7.2f prints a floating-point value with 5 positions to the left of the decimal point. d) The conversion specifier %7.2f prints a floating-point value with 4 positions to the left of the decimal point

D

4.41. Which statement is true? a) EOF must have the value 1 on all C systems. b) EOF is a symbolic constant defined in the <symbol.h> header file. c) EOF is a symbolic variable defined in the <stdio.h> header file. d) EOF is a symbolic integer constant defined in the <stdio.h> header file

D

4.45 Which of the following is false? (a) break and continue statements alter the flow of control. (b) continue statements skip the remaining statements in the body of the loop in which they are embedded. (c) break statements exit from the loop in which they are embedded. (d) continue and break statements may be embedded within all C++ structures.

D

4.46. Which statement is true? a) The break statement causes an immediate exit from a while, for, do ... while or if ... else statement. b) The continue statement is designed for use with the while, for, do ... while or switch statements. c) An equivalent while statement for any for statement can always be formed. d) The break statement causes an immediate exit from a while, for, do ... while or switch statement.

D

4.49 The expression if ( num != 65 ) can not be replaced by: (a) if ( num > 65 || num < 65 ) (b) if !( num == 65 ) (c) if (num - 65) (d) if !(num - 65)

D

4.5. Which statement is false? a) Counter-controlled repetion is sometimes called definite repetition. b) Sentinel-controlled repetition is sometimes called indefinite repetition. c) The sentinel value typically indicates "end of data." d) In counter-controlled repetition, the control variable is always incremented by 1 each time the group of instructions is performed.

D

4.50 An operator that associates from right to left is (a) != (b) , (c) () (d) ?:

D

4.53. Which statement is true? a) Operator || has a higher precedence than operator &&. b) In expressions involving operator ||, making the condition that is most likely to be false the leftmost condition can often reduce execution time. c) The logical negation operator is a binary operator. d) In expressions using operator &&, making the condition that is most likely to be false the leftmost condition can often reduce execution time.

D

4.56 Of the following, which is not a logic error? (a) Using the assignment (=) operator instead of the (==) equality operator to determine if two values are equal (b) Dividing by zero (c) Failing to initialize counter and total variables before the body of a loop (d) Using commas instead of the two required semicolons in a for header

D

4.7 Which of the following does counter controlled repetition not require? (a) an initial value (b) a condition that tests for the final value (c) an increment or decrement by which the control variable is modified each time through the loop (d) counter controlled repetition requires all of the above

D

4.15. Which statement automatically handles all the details of counter-controlled repetition. a) for b) while c) do ...while d) continue

a