Reverse a string (without built-in reverse)?

Short answer: Logic Convert to char array. Swap characters from both ends. string str = "dotnet"; char[] chars = str.ToCharArray(); int left = 0, right = chars.Length - 1; while (left < right) { char temp = chars[left]; chars[left] = chars[right]; chars[right] = temp; left++; right--; } string reversed = new string(chars);

Example code

Logic Convert to char array. Swap characters from both ends. string str = "dotnet";
char[] chars = str.ToCharArray();
int left = 0, right = chars.Length - 1; while (left < right) {
char temp = chars[left];
chars[left] = chars[right];
chars[right] = temp; left++; right--; }
string reversed = new string(chars);

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.