谢谢楼上各位的讨论和回答。总结一下

package main

import (
"fmt"
)

func main() {
fmt.Println("Hello, playground")

a := []int{1,2,3,4,5,6}
printSlice(a)

b := a[1:3]
b[0] = 0
printSlice(b)

c := b[:3]
c[0] = 0
printSlice(c)

//d := c[-1:] 可惜不能往前扩
//printSlice(d)

d := c[1:4]
d[0] = 0
printSlice(d)

e := d[1:4] //通过小切片来移动窗口处理数据还是挺方便的。
e[0]=0
printSlice(e)

printSlice(a)
}

func printSlice(s []int) {
fmt.Printf("len=%d cap=%d %v\n", len(s), cap(s), s)
}


Hello, playground
len=6 cap=6 [1 2 3 4 5 6]
len=2 cap=5 [0 3]
len=3 cap=5 [0 3 4]
len=3 cap=4 [0 4 5]
len=3 cap=3 [0 5 6]
len=6 cap=6 [1 0 0 0 5 6]