Cleaner switch expressions with pattern matching in C#

C# switch expressions with pattern matching allow cleaner, more declarative code when mapping multiple values to the same result. The `or` keyword acts as a logical pattern combinator, letting you collapse multiple case labels into one arm. Combined with `and`, `not`, and relational patterns, switch expressions can handle ranges and negations elegantly. The `and` operator binds tighter than `or`, similar to `&&` vs `||`, so parentheses should be used when combining them. The discard pattern `_` serves as a safe default, making switch expressions a concise, self-documenting decision table.