Check if two numbers have opposite signs?

Short answer: public bool HaveOppositeSigns(int x, int y) { return (x ^ y) < 0; } Explanation: XOR of two numbers with opposite signs has the sign bit set (negative number).

Example code

public bool HaveOppositeSigns(int x, int y) {
return (x ^ y) < 0;
} Explanation: XOR of two numbers with opposite signs has the sign bit set (negative number).

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.