众所周知,golang中map是一个指针,既然是一个指针,那么参数传递、赋值应该都是指针传递,而下面的例子也印证了我的想法
go
package main
import "fmt"
func test_map2(m map[string]string) {
fmt.Printf("inner: %v, %p, %p\n", m, m, &m)
m = make(map[string]string, 0)
m["a"] = "11"
fmt.Printf("inner: %v, %p, %p\n", m, m, &m)
}
func main() {
// var m map[string]string //未初始化
m := make(map[string]string)
fmt.Printf("outer: %v, %p, %p\n", m, m, &m)
test_map2(m)
fmt.Printf("outer: %v, %p, %p\n", m, m, &m)
n := m
fmt.Printf("outer: %v, %p, %p\n", n, n, &n)
}
输出
go
outer: map[], 0xc0000160f0, 0xc000042020
inner: map[], 0xc0000160f0, 0xc000042030
inner: map[a:11], 0xc000016180, 0xc000042030
outer: map[], 0xc0000160f0, 0xc000042020
outer: map[], 0xc0000160f0, 0xc000042038