golang中map赋值

bob628562023-09-03 10:01

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 复制代码

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 复制代码

outer: map[], 0xc0000160f0, 0xc000042020
inner: map[], 0xc0000160f0, 0xc000042030
inner: map[a:11], 0xc000016180, 0xc000042030
outer: map[], 0xc0000160f0, 0xc000042020
outer: map[], 0xc0000160f0, 0xc000042038