Basic Calculator (Add, Subtract, Multiply, Divide)?

Short answer: double Calculate(double a, double b, char op)

Example code

{
return op switch
{ '+' => a + b, Follow on: '-' => a - b, '*' => a * b, '/' => b != 0 ? a / b : throw new DivideByZeroException(), _ => throw new ArgumentException("Invalid operator"), }; } Explanation: Simple switch statement performing basic arithmetic, with divide-by-zero check.

Real-world example (ShopNest)

In coding rounds, state complexity aloud, write a clear ShopNest-flavored example (orders, carts), then handle edge cases (empty list, null, overflow).

Say this in the interview

1. Define — one clear sentence (the short answer above).
2. Example — relate it to a project like ShopNest or your real work.
3. Trade-off — when you would not use it.