package main

import "fmt"

func main() {
	fmt.Printf("%x\n", 456)
	var m *int
	fmt.Printf("%s\n", m)
	//a := 10
	b := 10
	m = &b
	fmt.Printf("%d\n", *m)

	str := []string{"foo", "gomain"}
	for i,s := range str{
		fmt.Println(i, s)
	}

	// array
	arr := [5] int{1:9, 4:1}
	fmt.Println(arr)

	// arrayx2
	var value [][]int
	arr1 := []int{1, 2, 3}
	arr2 := []int{4, 5, 6}
	value = append(value, arr1)
	value = append(value, arr2)
	fmt.Println(value[0])
	for i:=0; i<2; i++{
		for j:=0; j<3; j++{
			fmt.Print(value[i][j])
		}
	}

	var  ptr *int

	fmt.Printf("\nptr 的值为 : %x\n", ptr  )

	f1, f2 := 10, 20
	fmt.Println(f1, f2)
	swap(&f1, &f2)
	fmt.Println(f1, f2)
}

func swap(a, b *int){
	temp := *a
	fmt.Println(*a)
	*a = *b
	*b = temp
}