1 public class Horse {
2 Horse same;
3 String jimmy;
4
5 public Horse(String lee) {
6 jimmy = lee;
7 }
8
9 public Horse same(Horse horse) {
10 if (same != null) {
11 Horse same = horse;
12 same.same = horse;
13 same = horse.same;
14 }
15 return same.same;
16 }
17
18 public static void main(String[] args) {
19 Horse horse = new Horse("youve been");
20 Horse cult = new Horse("horsed");
21 cult.same = cult;
22 cult = cult.same(horse);
23 System.out.println(cult.jimmy);
24 System.out.println(horse.jimmy);
25 }
26 }
输出的结果是
horsed youve been
原因在于，在第14行结束后，局部变量same（就是指向horse的那个same）就被销毁了，此时15行的same是cult 的same， return same.same 就是return cult自己。
1 public class Foo {
2 public int x, y;
3 public Foo (int x, int y) {
4 this.x = x;
5 this.y = y;
6 }
7
8 public static void switcheroo (Foo a, Foo b) {
9 Foo temp = a;
10 a = b;
11 b = temp;
12 }
13
14 public static void fliperoo (Foo a, Foo b) {
15 Foo temp = new Foo(a.x, a.y);
16 a.x = b.x;
17 a.y = b.y;
18 b.x = temp.x;
19 b.y = temp.y;
20 }
21
22 public static void swaperoo (Foo a, Foo b) {
23 Foo temp = a;
24 a.x = b.x;
25 a.y = b.y;
26 b.x = temp.x;
27 b.y = temp.y;
28 }
29
30 public static void main (String[] args) {
31 Foo foobar = new Foo(10, 20);
32 Foo baz = new Foo(30, 40);
33 switcheroo(foobar, baz); //foobar.x: ___ foobar.y: ___ baz.x: ___ baz.y: ___
34 fliperoo(foobar, baz); //foobar.x: ___ foobar.y: ___ baz.x: ___ baz.y: ___
35 swaperoo(foobar, baz); //foobar.x: ___ foobar.y: ___ baz.x: ___ baz.y: ___
36 System.out.println();
37 }
38 }
10 20 30 40
30 40 10 20
10 20 10 20
33 行我有点不太明白。
其实传入到函数Switcheroo的时候，a 和 b 都仅仅是指向foobar and baz，所以 a = b 就仅仅只是改变了a 的指向罢了，从指向foobar 到指向 baz.
标签：week2,CS61B,baz,same,foobar,discussion3,___,Foo,public From： https://www.cnblogs.com/xuenima/p/17379329.html