Lambdas vs Anonymous Inner Classes (Scope and Performance).

1. Scope

• this keyword: In an anonymous class, this refers to the anonymous class itself. In a lambda, this refers to the enclosing class.
• Variables: Both can access effectively final local variables.

2. Performance (and Compilation)

• Class Files: Anonymous classes generate a separate .class file (e.g., Main.class). Lambdas do not; they use invokedynamic (Java 7+ feature) to create a call site.
• Memory: Lambdas are generally more memory-efficient as they don't always create a new object instance (depending on whether they capture state).