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PCEP Certification Practice Test: Iterating Through Lists with the for Loop

Here are 25 questions focusing on the topic "iterating through lists with the for loop" for the PCEP-30-02 certification exam. The questions are presented in various formats, including single-select, multiple-select, gap fill, code insertion, sort, and "rearrange" questions. Each question includes the correct answer and an explanation.

Question 1: Which of the following is the correct syntax to iterate through a list named my_list using a for loop?

  1. for x in range(len(my_list))
  2. for x in my_list
  3. for x in list
  4. for x in range(my_list)
▼

Answer: b) for x in my_list

Explanation: Option b) is the correct way to directly iterate over elements in a list using a for loop.

Question 2: What will be the output of the following code?

fruits = ["apple", "banana", "cherry"]
for fruit in fruits:
    print(fruit)
  1. ["apple", "banana", "cherry"]
  2. apple banana cherry
  3. apple, banana, cherry
  4. fruit
▼

Answer: b) apple banana cherry

Explanation: The for loop iterates over each element in the list and prints it on a new line.

Question 3: Which of the following code snippets correctly iterates through a list by index?

  1. for i in range(list)
  2. for i in range(my_list): print(i)
  3. for i in range(len(my_list)): print(my_list[i])
  4. for i in range(len(my_list)): print(i)
▼

Answer: c) for i in range(len(my_list)): print(my_list[i])

Explanation: Option c) uses range(len(my_list)) to iterate over the indices and access each element in the list.

Question 4: Which of the following are valid ways to iterate over a list using a for loop? (Choose all that apply)

  1. for x in my_list:
  2. for x in range(len(my_list)):
  3. for x in enumerate(my_list):
  4. for i in range(len(my_list)):
▼

Answer: a) for x in my_list:, d) for i in range(len(my_list)):

Explanation: Option a) iterates directly over the elements, and option d) iterates over the indices, accessing the elements via my_list[i]. Option b) lacks the proper indexing method and option c) would require unpacking.

Question 5: Which of the following approaches can be used to iterate over a list and get both index and value? (Choose two)

  1. for i in range(len(my_list)): print(i, my_list[i])
  2. for i, value in enumerate(my_list): print(i, value)
  3. for value in my_list: print(value, i)
  4. for i, x in range(len(my_list)): print(i, x)
▼

Answer: a) for i in range(len(my_list)): print(i, my_list[i]), b) for i, value in enumerate(my_list): print(i, value)

Explanation: Option a) and b) both correctly retrieve both the index and value during iteration. Option c) is incorrect because i is not defined. Option d) has incorrect syntax.

Question 6: The loop for __________ in my_list: is used to iterate through each element of my_list.

▼

Answer: element

Explanation: The loop variable (element) takes the value of each element in my_list during iteration.

Question 7: The loop for __________ in range(len(my_list)): is commonly used to iterate through a list by index.

▼

Answer: i

Explanation: The loop variable i is typically used as an index while iterating through a list with range(len(my_list)).

Question 8: Arrange the following code statements in the correct order to iterate over a list and print each element:

  1. for item in my_list:
  2. print(item)
  3. my_list = [1, 2, 3, 4]
▼

Answer: c) my_list = [1, 2, 3, 4]
a) for item in my_list:
b) print(item)

Explanation: The list is defined first, then the for loop is used to iterate over the elements, and each element is printed.

Question 9: Arrange the following steps to iterate over a list by index and print the elements:

  1. for i in range(len(my_list)):
  2. print(my_list[i])
  3. my_list = ["a", "b", "c"]
▼

Answer: c) my_list = ["a", "b", "c"]
a) for i in range(len(my_list)):
b) print(my_list[i])

Explanation: First, the list is defined, then a loop is used to iterate through the list by index, and finally, the elements are printed.

Question 10: Complete the code to print each element of the list names:

names = ["John", "Jane", "Doe"]
for __________:
    print(name)
▼

Answer: name in names

Explanation: The correct loop is for name in names: to iterate over each element in the list and print it.

Question 11: Complete the code to iterate through a list by index and print each element in reverse order:

items = [1, 2, 3, 4]
for __________:
    print(items[i])
▼

Answer: in range(len(items)-1, -1, -1)

Explanation: The loop for i in range(len(items)-1, -1, -1) iterates through the list indices in reverse order.

Question 12: Insert the correct code to print the index and value of each element in the list colors:

colors = ["red", "green", "blue"]
__________
    print(index, value)
▼

Answer: for index, value in enumerate(colors):

Explanation: The enumerate() function allows you to loop over the list and retrieve both index and value simultaneously.

Question 13: Insert the correct code to iterate over the list numbers and print only even numbers:

numbers = [1, 2, 3, 4, 5, 6]
__________
    if num % 2 == 0:
        print(num)
▼

Answer: for num in numbers:

Explanation: The loop for num in numbers: iterates over the list and the if condition checks for even numbers.

Question 14: 14. Rearrange the code to iterate over a list and print each element:

  1. my_list = [10, 20, 30]
  2. print(item)
  3. for item in my_list:
▼

Answer: a)my_list = [10, 20, 30]
c) for item in my_list:
b) print(item)

Explanation: The list is defined first, followed by the loop initialization, and then the elements are printed.

Question 15: Organize the steps to iterate through a list of names and print each one:

  1. for name in names:
  2. print(name)
  3. names = ["Alice", "Bob", "Charlie"]
▼

Answer: c) names = ["Alice", "Bob", "Charlie"]
a) for name in names:
b) print(name)

Explanation: The list is created first, followed by the loop to iterate through it, and each element is printed.

Question 16: What does the following code output?

nums = [5, 10, 15]
for num in nums:
    print(num * 2)
  1. 5 10 15
  2. 10 20 30
  3. 25 50 75
  4. Error
▼

Answer: b) 10 20 30

Explanation: The loop multiplies each element by 2 and prints the result.

Question 17: What does the following code output?

names = ["Anna", "Bob", "Clara"]
for i in range(len(names)):
    print(names[i])
  1. Anna Bob Clara
  2. 0 1 2
  3. ["Anna", "Bob", "Clara"]
  4. Error
▼

Answer: a) Anna Bob Clara

Explanation: The loop iterates by index and prints each element in the list.

Question 18: Using a for loop to iterate over a list allows you to access each element directly.

  1. True
  2. False
▼

Answer: a) True

Explanation: The loop for element in list: directly accesses each element during iteration.

Question 19: You can only iterate over lists by their indices using a for loop.

  1. True
  2. False
▼

Answer: b) False

Explanation: You can iterate directly over elements without needing to use indices.

Question 20: What happens if you iterate over an empty list using a for loop?

  1. It raises an error
  2. The loop runs indefinitely
  3. The loop does nothing
  4. The list is cleared
▼

Answer: c) The loop does nothing

Explanation: Iterating over an empty list results in no iterations and no output.

Question 21: Which of the following statements about for loops is correct?

  1. A for loop can only be used with lists.
  2. A for loop must always use range().
  3. You can iterate through any iterable using a for loop.
  4. for loops do not work with strings.
▼

Answer: c) You can iterate through any iterable using a for loop.

Explanation: for loops work with any iterable, including lists, tuples, strings, and more.

Question 22: What will happen if you modify a list while iterating over it using a for loop?

  1. The loop will skip some elements
  2. The loop will raise an error
  3. The loop will continue normally
  4. The loop will restart from the beginning
▼

Answer: a) The loop will skip some elements

Explanation: Modifying a list while iterating over it can lead to unexpected behavior, like skipping elements.

Question 23: Fill in the blank: The for loop is commonly used to iterate through __________ in a list.

▼

Answer: elements

Explanation: The for loop iterates through elements in a list.

Question 24: The function enumerate() can be used to retrieve both __________ and values when iterating through a list.

▼

Answer: indices

Explanation: enumerate() returns both the index and the value during iteration.

Question 25: What is the output of the following code?

animals = ["dog", "cat", "bird"]
for animal in animals:
    print(animal.upper())
  1. dog cat bird
  2. Dog Cat Bird
  3. DOG CAT BIRD
  4. Error
▼

Answer: c) DOG CAT BIRD

Explanation: The loop converts each element to uppercase using .upper() and then prints it.

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