How does raw types impact performance or memory usage?

Raw types in Java can impact performance and memory usage significantly, especially in a situation where generics are used. When raw types are utilized, type safety is compromised, which can lead to runtime exceptions and potentially increased memory overhead due to the need for additional type checks.

Using raw types means that the Java compiler cannot perform certain optimizations that it could when using parameterized types. This may lead to increased memory usage, as the raw type may lead to the creation of unnecessary wrapper objects. In addition, the lack of generics can result in more frequent casting, which can further degrade performance.

// Using raw types example
List rawList = new ArrayList(); // Raw type usage
rawList.add("String as a raw type");
String str = (String) rawList.get(0); // Requires casting