package main //必须有个main包

import "fmt"

func swap(p1, p2 *int) {
	*p1, *p2 = *p2, *p1
}

func main() {
	a, b := 10, 20

	//通过一个函数交换a和b的内容
	swap(&a, &b) //地址传递
	fmt.Printf("main: a = %d, b = %d\n", a, b)
}

main: a = 20, b = 10