我有兩個(gè)來(lái)自同一類的對(duì)象，稱其為“第一”和“第二”。我有一個(gè)接受對(duì)象的方法，所以我使用“第一個(gè)”對(duì)象，調(diào)用該方法，將“第二個(gè)”對(duì)象傳遞給該方法。在該方法中，為什么我可以訪問(wèn)“第二個(gè)”對(duì)象的私有實(shí)例變量？我說(shuō)的有道理嗎？// Day.java, basic example of my questionpublic class Day{  private int stuff = 1;  public Day(int stuff){   this.stuff = stuff;  }  public int m(Day d){ // This method takes in an object as a parameter   int add = 0;   add = this.day + d.day; // why can you do this? isn't "day" private?   return add;  }}