go语言函数传递问题（map、切片、接口、chan）

package main

import (

"fmt"

)

func change(a int) {

a = 10

}

func changeMap(m map[int]string) {

_, ok := m[1]

if ok {

m[1] = "jack"

}

}

func changeSlice(s []int) {

s[0] = 10

}

func changeChan(ch chan int) {

ch <- 99

}

func main() {

key := 10

change(key)

fmt.Println(key)

m := make(map[int]string)

m[1] = "may"

changeMap(m)

fmt.Println(m)

s := []int{1, 2, 3}

changeSlice(s)

fmt.Println(s)

ch := make(chan int, 3)

changeChan(ch)

fmt.Println(<-ch)

close(ch)

}