Question

If a read-loop is written to process an unknown number of values using the while construct, and if there is one read before the while instruction there will also be one __________.

	a.	at the bottom of the body of the loop
	b.	in the middle of the body of the loop
	c.	at the top of the body of the loop
	d.	there are no other reads

Answer 1

The correct option is a

Explanation:

Consider the following algorithm/pseudocode to read unknown number of values from a file and compute their sum:

infile = open(“sample.txt”, ‘r’)

value = infile.readline()

sum = 0

while (value != EOF):

{

     // Perform the operation on the value.

     sum = sum + int(value1)

     // Read the next line.

     value = infile.readline()

}

infile.close()

print(sum)

• As shown above, the first read instruction is written before the loop.
• The value is compared at the starting of the while loop.
• The next read instruction is written at the bottom of the loop after all the operations on the current value have been performed so the value can be compared in the next iteration.

Hence, the correct answer is option a, at the bottom of the body of the loop.