Group employees by department 📝 To print the groups: foreach (var group in grouped) { Console.WriteLine($"Department: {group.Key}"); foreach (var emp in group) Console.WriteLine($" - {emp.Name}"); }

Short answer: var grouped = employees .GroupBy(e => e.Department); Each group is an IGrouping<string, Employee>

Example code

var grouped = employees
.GroupBy(e => e.Department); Each group is an IGrouping<string, Employee>

Real-world example (ShopNest)

A sales report joins orders and customers, then GroupBy(c => c.City) to show revenue per city.

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.