Array — DSA Technical Interview Questions & Answers

Array

Array

  • Array is a DSA topic. In plain words you use it for marks[0..n-1] in a class list. Don’t start with a slogan — start with that picture.
  • Smallest example: index access O(1). Type it, run it, and say what you see. If you can do that from memory, you know Array.
  • From the example next to this theory: Arrays give O(1) index access; matrices are arrays of arrays.
  • Trap: off-by-one on the last index. Fix that before you talk about advanced DSA.
  • Viva: what is Array? Then show index access O(1). Then name the trap.

Technical Interview Tip: What is Array? Show this: index access O(1). Trap: off-by-one on the last index.

Code Examples for Array

Array — working example

arr = [10, 20, 30, 40]
print(arr[2], arr[-1])
matrix = [[1, 2], [3, 4]]
print(matrix[1][0])  # 3

Arrays give O(1) index access; matrices are arrays of arrays.

How to Explain Array to an Interviewer

What is Array?

Used for marks[0..n-1] a class list Not just the heading

Give one small example of Array.

index access O(1) Arrays give O(1) index access; matrices are arrays of arrays

What mistake do beginners make with Array?

off-by-one on the last index Show the fix

Where do you use Array?

a class list marks[0..n-1]