2022-08-03: What does the following go code output?A: 2; B: 3; C: 1; D: 0.package main import "fmt" func main() { slice := []i

2022-08-03：以下go语言代码输出什么？A：2;B：3;C：1;D：0.

package main

import "fmt"

func main() {
    

    slice := []int{
    0, 1, 2, 3}
    m := make(map[int]*int)

    for key, val := range slice {
    
        m[key] = &val
    }

    fmt.Println(*m[2])
}

答案2022-08-03：

答案选B.val只会定义一次,等价于以下代码.

import (
	"fmt"
)

func main() {
    

	slice := []int{
    0, 1, 2, 3}
	m := make(map[int]*int)

	key := 0
	val := 0
	for key < len(slice) {
    
		val = slice[key]
		m[key] = &val
		key++
	}

	fmt.Println(*m[2])
}