下面代码的运行输出结果是 public class Test { public static void main(String args[]) { int x = 0; if (x > 0) x = 1; switch (x) { case 1: System. out .println(1); case 0: System. out .println(0); case 2: System. out .println(2); break ; case 3: System. out .println(3); default : System. out .println(4); break ; } } }