下列A类中【代码1】~【代码4】哪些是错误的? 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.f(); //【代码4】 tom.g(); } }