Q: What is an off-by-one error?

It is a logical bug where a loop boundary is miscalculated, causing the loop to execute one time too many or one time too few.

Q: Why do arrays start at index 0?

It relates to memory addressing. The index represents the memory offset from the starting position of the array. The first element has an offset of 0.

Q: What happens if a loop stops one iteration early?

Your code will run without crashing, but it will skip the final element, resulting in an incorrect output or a failed test case.

Question 1

How do I prevent index out of bounds errors?

Accepted Answer

Always ensure your loop condition uses strictly less than (<) the array's length, rather than less than or equal to (<=).

Question 2

What is an off-by-one error?

Accepted Answer

It is a logical bug where a loop boundary is miscalculated, causing the loop to execute one time too many or one time too few.

Question 3

Why do arrays start at index 0?

Accepted Answer

It relates to memory addressing. The index represents the memory offset from the starting position of the array. The first element has an offset of 0.

Question 4

What happens if a loop stops one iteration early?

Accepted Answer

Your code will run without crashing, but it will skip the final element, resulting in an incorrect output or a failed test case.

How do I prevent index out of bounds errors?

More FAQs in Common Off-By-One Errors in For Loops

Still have questions?

Want to upskill yourself?

Small steps. Big possibilities.

Our courses are taking a Coffee break, but your curiosity shouldn't. Stay engaged with namastedev linkedin, youtube, discord and other resources while you wait.