圍棋

Question

修改結構內的結構片在下面的例子中，一個person有friendship秒的片，我嘗試初始化friendship作爲指針到另一個person對象，但由於某種原因失敗，而結果是沒有人有任何friendship s。我不在某處應該使用指針嗎？

package main 

import (
    "fmt" 
    "math/rand" 
) 

type friendship struct { 
    friend *person 
} 

type person struct { 
    name  int 
    friendship []friendship 
} 

func createPerson(id int) person { 
    return person{id, make([]friendship, 0)} 
} 

func (p *person) addFriends(possibleFriends []*person, numFriends int) { 
    var friend *person 
    for i := 0; i < numFriends; i++ { 
     friend = possibleFriends[rand.Intn(len(possibleFriends))] 
     p.friendship = append(p.friendship, friendship{friend}) 
    } 
} 

func main() { 
    numPeople := 20 
    people := make([]person, numPeople) 
    possibleFriends := make([]*person, numPeople) 
    for i := 0; i < numPeople; i++ { 
     people[i] = createPerson(i) 
     possibleFriends[i] = &(people[i]) 
    } 
    for _, p := range people { 
     p.addFriends(possibleFriends, 2) 
    } 
    fmt.Println(people) 
} 

Answer 1

使用

for i := 0; i < numPeople; i++ { 
     people[i].addFriends(possibleFriends, 2) 
} 

或

for i, _ := range people { 
     people[i].addFriends(possibleFriends, 2) 
} 

，而不是

for _, p := range people { 
     p.addFriends(possibleFriends, 2) 
} 

這是因爲p是people[i]副本，addFriends沒有EFF ECT片上people