What is a local class's access to effectively-final local variables, and how does this same rule (and the underlying reason for it) apply identically to anonymous classes and lambdas?

Both local classes and anonymous classes can access local variables from their enclosing method scope, but ONLY if those variables are effectively final (never reassigned after initialization) -- this is the exact same rule and underlying reason discussed for lambda variable capture: since the local/anonymous class instance might outlive the method call that created it (e.g., stored and invoked later on a different thread), the compiler captures a fixed COPY of each accessed local variable's value at creation time rather than a live reference to the original variable, and permitting reassignment after that copy was made would create confusing, ill-defined semantics about which value the class 'sees'.

public Runnable makeRunnable() {
    int count = 5;
    // count = 10;  // if uncommented AFTER the class below references count, COMPILE ERROR

    class LocalTask implements Runnable {
        public void run() { System.out.println("Count was: " + count); }  // captures count's value
    }
    return new LocalTask();
}