Class 10 Computer Science — Changing and growing a list

1.A list holds four values, and a program runs the line values[4] = 7. Why is that a mistake?

• a) There is no position 4 yet, and writing to a position can only change a value that is already there
• b) The list would end up five values long with a gap in the middle of it
• c) Position 4 is the first position, and it already holds a value
• d) Writing to a position is never allowed once a list has been made

2.Something is added on the end, and then a position from before the change is asked for. What does the program print?

marks = [12, 7, 20]
marks.append(5)
print(marks[2])

3.Something is added on the end and something else is written over. What does this program print?

row = [2, 4, 6]
row.append(8)
row[0] = 10
print(row[0] + row[3])

4.A value is written over, and then the list is measured. What does this program print?

sizes = [5, 2, 9]
sizes[0] = 40
print(len(sizes))

5.A list called box already holds four values. Sort each line by what it does to how long the list is.

6.Two lists are joined into a third one here. What does this program print?

first = [1, 2]
second = [7, 8, 9]
both = first + second
print(len(both))

7.One value is added on the end of this list. What number does the program print?

queue = [4, 9]
queue.append(6)
print(len(queue))

8.A list holds five values. One of its values is written over, and then one more value is added on the end. How many values does the list hold now?

• a) 4
• b) 6
• c) 7
• d) 5