Core Java: A local class declared inside a method is visible only inside that method

A class declared inside a method body exists only for the duration of that call and cannot be referenced from outside it, making it useful for a small helper type needed in one place.

Code

static String describe() {
    class Local {
        String greet() { return "hello from a local class"; }
    }
    Local l = new Local();
    return l.greet();
}
System.out.println(describe());

Output

hello from a local class