下列A类中【代码1】~【代码4】哪个是错误的? class Tom { private int x = 120; protected int y = 20; int z = 11; private void f() { x = 200; System.out.println(x); } void g() { x = 200; System.out.println(x); } } public class A { public static void main(String args[]) { Tom tom = new Tom(); tom.x = 22; //【代码1】 tom.y = 33; //【代码2】 tom.z = 55; //【代码3】 tom.g(); //【代码4】 } }