golang之array

golang使用array表示固定大小的數組，使用slice表示動态數組。

package main

import "fmt"

func main() {
	var a = [5]int{2,3,5,7,11}
	fmt.Printf("type of array: %T\n", a)
	fmt.Printf("address of array: %p\n", &a)
	fmt.Printf("address of arrar[0]: %p\n", &a[0])

	s := a[:]
	fmt.Printf("slice = %v, len = %d, cap = %d\n", s, len(s), cap(s))
	fmt.Printf("address of slice: %p\n", &s)
	fmt.Printf("address of slice[0]: %p\n", &s[0])

	s = append(s, 13)
	fmt.Printf("slice = %v, len = %d, cap = %d\n", s, len(s), cap(s))
	fmt.Printf("address of slice: %p\n", &s)
	fmt.Printf("address of slice[0]: %p\n", &s[0])
}　　      

輸出如下:

type of array: [5]int

address of array: 0xc420014150

address of arrar[0]: 0xc420014150

slice = [2 3 5 7 11], len = 5, cap = 5

address of slice: 0xc42000a060

address of slice[0]: 0xc420014150

slice = [2 3 5 7 11 13], len = 6, cap = 10

address of slice[0]: 0xc42001c0f0

參考資料:

Slices: usage and internals 

https://golang.org/pkg/builtin/#append