为什么java在本地时要求初始化变量

Please see the code below. The method printTest() is printing the default value of the uninitialized variables but when it's comes to main method java is asking for variable initialization. Can anybody explain why?

   public class Test1 {

    public static void main(String[] args) {   
      int j;
      String t;

      System.out.println(j);
      System.out.println(t);
    }
  }


  public class Test2 {

   int i;
   String test;

  public static void main(String[] args)   {   
    new Test().printTest();
  }

   void printTest()   {
     System.out.println(i);
     System.out.println(test);
  }

  }

推荐答案

局部变量主要用于中间计算，而实例变量应该携带用于未来和中间计算的数据.Java 不强制初始化实例变量并允许默认值，但对于局部变量，开发人员调用它来分配值.所以为了避免错误，你需要初始化局部变量.