Chapter 8: JavaScript: Control Statements II

8.1 Which of the following is not required for counter-controlled repetition?

a) final value

b) initial value

c) sentinel

d) increment

c

8.2 What should you use as a counter in counter-controlled repetition?

a) a floating-point number

b) a sentinel

c) an integer

d) a num object

c

8.3 What would the browser display if the following script were executed?

a) Nothing; the script would generate an error

b) XXXX

c) XXXXX

d) XXXXXX

a

8.4 What would the browser display if the following script were executed?

a) Nothing; the script would generate an error

b) OOOO

c) OOOOO

d) OOOOOO

c

8.5 Which of the following is declared correctly and will not result in an error, assuming x = 2 and y = 30?

a) for ( var j = 10; j <= 80; j-- )

b) for ( var j = x, j <= y, j += 5 )

c) for ( var j = x; j <= 80 * y; j += 5 / x )

d) for ( var j = x; j <= 80 * y; j -= 5 )

c

8.6 What is the value of num after the following statement is performed?

num = 2 * Math.pow( 2, 3 );

a) 16

b) 18

c) 64

d) 8

a

8.7 What is the value of num after the following statements are performed?

num = 2.4589;

num = num.toFixed( 2 );

a) 2

b) 2.46

c) 2.5

d) 2.45

b

8.8 The ________ multiple-selection statement is used to handle decision making and can be used to replace multiple if and if...else statements.

a) do...while

b) case

c) break

d) switch

d

8.9 switch statements contain ________ labels.

a) select

b) if...else

c) case

d) choice

c

8.10 In a switch statement, the ________ case clause is used to process exceptional conditions and is usually listed last.

a) break

b) default

c) else

d) then

b

8.11 Consider the following code selections. Assume count is initialized to 7 and num is initialized to 0.

i) ii)

do

{ while ( count < 6 )

num = count; num = count;

} while ( count < 6 )

What will the value of num be for i) and ii) respectively after the loops have been executed?

a) 0, 0

b) 0, 7

c) 7, 0

d) 7, 7

c

8.12 What would the browser display if it executed the following script?

a) Nothing; the script would generate an error

b) O

c) OOOOO

d) OOOOOO

b

8.13 What would the browser display if it executed the following script?

a) Nothing; the script would generate an error.

b) 1

c) 5

d) 10

c

8.14 What would the browser display if it executed the following script?

a) Nothing; the script would generate an error.

b) 5

c) 9

d) 10

d

8.15 Which of the following will not evaluate to true?

a) false || false

b) true || true

c) false || true

d) true || false

a

8.16 Which of the following will not evaluate to false?

a) false && false

b) true && true

c) false && true

d) true && false

b