java - 从 main 调用方法会抛出 NullPointerException

Question

我尝试从我的 main 方法调用方法 ss，但它抛出以下异常

Exception in thread "main" java.lang.NullPointerException
        at teste1.exp.ss(exp.java:16)
        at teste1.Main.main(Main.java:64)
Java Result: 1

public class Main {
   public static void main(String[] arguments) {
...................
    private static String[] ff;
    exp mega = new exp();
mega.ss(ff);

}

class exp {

 public void ss (String gvanswer[]){


    String answer[] = new String[3];

            answer[0] = "pacific ";
            answer[1] = "everest";
            answer[2] = "amazon ";

    if (gvnswer[0].equals("pacific"))
   {System.out.println("eeeeeeeeeeeeee  ");}

  if (gvanswer[1].equals(answer[1])){System.out.println("l  ");}

    }

Answer 1

你调用了mega.ss(ff)但是ff从未被初始化过:

ff = new String[1];
ff[0] = "foo";