Relational and Logical Patterns

Pattern matching gets a lot more useful once you can ask questions like "is this price between 100 and 500?" or "is this order total over 1000 and not refunded?" without dragging a chain of && and || operators into your switch. Relational patterns (C# 9) compare a value against a constant with <, <=, >, >=, and logical patterns (and, or, not) glue them together. This lesson covers what they do, how they combine, where the boundaries are, and the small set of rules you need to keep them readable.