2023-05-26：golang关于垃圾回收和析构的选择题，代码如下： ```go package main import

package main

import (
    "fmt"
    "runtime"
    "time"
)

type ListNode struct {
    Val  int
    Next *ListNode
}

func main0() {
    a := &ListNode{Val: 1}
    b := &ListNode{Val: 2}
    runtime.SetFinalizer(a, func(obj *ListNode) {
        fmt.Printf("a被回收--")
    })
    runtime.SetFinalizer(b, func(obj *ListNode) {
        fmt.Printf("b被回收--")
    })
    a.Next = b
    b.Next = a
}

func main() {
    main0()
    time.Sleep(1 * time.Second)
    runtime.GC()
    time.Sleep(1 * time.Second)
    runtime.GC()
    time.Sleep(1 * time.Second)
    runtime.GC()
    time.Sleep(1 * time.Second)
    runtime.GC()
    time.Sleep(1 * time.Second)
    runtime.GC()
    fmt.Print("结束")
}