Unnamed Patterns and Variables

Java 22 introduced a tiny piece of syntax that fixes a surprisingly common annoyance: the underscore (_) as a stand-in for a variable or pattern you don't care about. Before this feature, every binding in a pattern needed a name, every catch clause needed a variable, and every lambda parameter needed an identifier, even when you were never going to read them. You'd invent names like unused, ignored, or tmp, and your IDE would still light up with "unused variable" warnings. This lesson covers where _ is allowed, where it isn't, and why being explicit about "I don't care" is a real readability win in e-commerce code that deconstructs orders, customers, and discounts.