Array traversal in C++ - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does array traversal mean in programming?

Array traversal means going through each element of an array one by one to read or process them.

beginner

How do you write a basic for loop to traverse an array in C++?

You use a for loop with an index starting at 0 up to the array size minus one, accessing each element by its index.

beginner

Why is it important to know the size of the array when traversing it?

Knowing the size prevents accessing elements outside the array, which can cause errors or crashes.

beginner

What is the output of this code?<br>

int arr[] = {1, 2, 3};
for(int i = 0; i < 3; i++) {
  std::cout << arr[i] << " ";
}

The output is: 1 2 3 <br>It prints each element of the array separated by spaces.

intermediate

Can you traverse an array backwards? How?

Yes, by starting the loop index at the last element (size - 1) and decreasing it until 0.

What is the starting index for traversing a C++ array?

A Array size

B 1

C -1

D 0

C++ arrays start at index 0, so traversal begins from 0.

Which loop is commonly used for array traversal in C++?

A for loop

B while loop

C do-while loop

D if statement

The for loop is most common because it easily controls the index.

What happens if you access an array element outside its bounds?

A It prints zero

B It automatically resizes the array

C Program may crash or show garbage values

D Nothing happens

Accessing outside bounds leads to undefined behavior, often crashes or wrong data.

How do you know how many times to loop when traversing an array?

A Use the array size

B Loop forever

C Use random number

D Loop once

Looping exactly the array size times ensures all elements are visited.

Which of these is a valid way to traverse an array backwards?

A for(int i = 1; i <= size; i++)

B for(int i = size - 1; i >= 0; i--)

C while(i < size)

D for(int i = 0; i < size; i++)

Starting from the last index and decreasing visits elements in reverse order.

Explain how to traverse an array in C++ using a for loop.

Think about how you count from the first to the last element.

Why must you be careful about array size when traversing?

Imagine walking on a path that ends at a certain point.