2.2.2 - 2.2.3 Iteration Extra Practice

What is the main condition for a `while` loop to keep running?

• As long as a list is not empty

• As long as the condition is True

• Until the function ends

• As long as a variable is undefined

Answer explanation

A `while` loop continues to execute as long as its condition evaluates to True. This means that the loop will keep running until the condition becomes False, making 'As long as the condition is True' the correct choice.

What kind of loop runs indefinitely if the condition never becomes false?

• Controlled loop

• Break loop

• Infinite loop

• Timed loop

Answer explanation

An infinite loop occurs when the loop's condition never evaluates to false, causing it to run endlessly. This is in contrast to controlled, break, or timed loops, which have defined exit conditions.

What will this code print? counter = 0 while counter < 3: print(counter) counter += 1

• 0 1 2

• 1 2 3

• 0 1 2 3

• 1 2

Answer explanation

The code initializes a counter at 0 and prints it while it is less than 3. It increments the counter after each print. Thus, it prints 0, 1, and 2 before the loop ends, making '0 1 2' the correct answer.

Which operator is typically used to check a condition in a `while` loop?

• +

• ==

• =

• %

Answer explanation

The '==' operator is used to compare values for equality in a condition. In a 'while' loop, it checks if the specified condition is true, allowing the loop to continue executing.

What does a `for` loop iterate over?

• Only strings

• Only numbers

• A sequence

• A condition

Answer explanation

A `for` loop iterates over a sequence, which can include lists, strings, or other iterable objects. This allows it to process each element in the sequence, making 'A sequence' the correct choice.

Which keyword is used to start a `for` loop in Python?

• iterate

• loop

• for

• range

Answer explanation

The keyword used to start a `for` loop in Python is 'for'. This keyword allows you to iterate over a sequence (like a list or a range) and execute a block of code for each item in that sequence.

What is the correct structure for a `for` loop?

• for i = range(5)

• for i in range(5):

• loop i in range(5):

• for (i in range 5)

Answer explanation

The correct structure for a `for` loop in Python is 'for i in range(5):'. This syntax correctly uses 'in' to iterate over the range and includes a colon at the end, which is required to define the loop block.

Which situation is best for a `for` loop?

• Only strings

• Only numbers

• Iterating over a sequence

• A condition

Answer explanation

A `for` loop is best used for iterating over a sequence, such as lists or strings, allowing you to access each element in a structured way. This makes 'Iterating over a sequence' the correct choice.

What does the `break` statement do?

• Pauses the loop

• Skips one loop cycle

• Ends the loop immediately

• Repeats the loop

Answer explanation

The `break` statement is used to end the loop immediately, terminating its execution and transferring control to the statement following the loop. This is why 'Ends the loop immediately' is the correct choice.

When is `break` commonly used?

• When a value reaches a limit

• To reset a loop

• To increase a variable

• In variable declarations

Answer explanation

The `break` statement is commonly used to exit a loop when a specific condition is met, such as when a value reaches a limit. This allows for controlled termination of the loop, making it the correct choice.