go Slice 切片语法
切片是一种动态数组，比数组操作灵活，长度不是固定的，可以进行追加和删除。len() 和 cap() 返回结果可相同和不同。
声明切片
1//demo_7.go
2package main
3
4import (
5 "fmt"
6)
7
8func main() {
9 var sli_1 [] int //nil 切片
10 fmt.Printf("len=%d cap=%d slice=%v\n",len(sli_1),cap(sli_1),sli_1)
11
12 var sli_2 = [] int {} //空切片
13 fmt.Printf("len=%d cap=%d slice=%v\n",len(sli_1),cap(sli_2),sli_2)
14
15 var sli_3 = [] int {1, 2, 3, 4, 5}
16 fmt.Printf("len=%d cap=%d slice=%v\n",len(sli_3),cap(sli_3),sli_3)
17
18 sli_4 := [] int {1, 2, 3, 4, 5}
19 fmt.Printf("len=%d cap=%d slice=%v\n",len(sli_4),cap(sli_4),sli_4)
20
21 var sli_5 [] int = make([] int, 5, 8)
22 fmt.Printf("len=%d cap=%d slice=%v\n",len(sli_5),cap(sli_5),sli_5)
23
24 sli_6 := make([] int, 5, 9)
25 fmt.Printf("len=%d cap=%d slice=%v\n",len(sli_6),cap(sli_6),sli_6)
26}
截取切片
1//demo_8.go
2package main
3
4import (
5 "fmt"
6)
7
8func main() {
9 sli := [] int {1, 2, 3, 4, 5, 6}
10 fmt.Printf("len=%d cap=%d slice=%v\n",len(sli),cap(sli),sli)
11
12 fmt.Println("sli[1] ==", sli[1])
13 fmt.Println("sli[:] ==", sli[:])
14 fmt.Println("sli[1:] ==", sli[1:])
15 fmt.Println("sli[:4] ==", sli[:4])
16
17 fmt.Println("sli[0:3] ==", sli[0:3])
18 fmt.Printf("len=%d cap=%d slice=%v\n",len(sli[0:3]),cap(sli[0:3]),sli[0:3])
19
20 fmt.Println("sli[0:3:4] ==", sli[0:3:4])
21 fmt.Printf("len=%d cap=%d slice=%v\n",len(sli[0:3:4]),cap(sli[0:3:4]),sli[0:3:4])
22}
追加切片
1//demo_9.go
2package main
3
4import (
5 "fmt"
6)
7
8func main() {
9 sli := [] int {4, 5, 6}
10 fmt.Printf("len=%d cap=%d slice=%v\n",len(sli),cap(sli),sli)
11
12 sli = append(sli, 7)
13 fmt.Printf("len=%d cap=%d slice=%v\n",len(sli),cap(sli),sli)
14
15 sli = append(sli, 8)
16 fmt.Printf("len=%d cap=%d slice=%v\n",len(sli),cap(sli),sli)
17
18 sli = append(sli, 9)
19 fmt.Printf("len=%d cap=%d slice=%v\n",len(sli),cap(sli),sli)
20
21 sli = append(sli, 10)
22 fmt.Printf("len=%d cap=%d slice=%v\n",len(sli),cap(sli),sli)
23}
删除切片
1//demo_10.go
2package main
3
4import (
5 "fmt"
6)
7
8func main() {
9 sli := [] int {1, 2, 3, 4, 5, 6, 7, 8}
10 fmt.Printf("len=%d cap=%d slice=%v\n",len(sli),cap(sli),sli)
11
12 //删除尾部 2 个元素
13 fmt.Printf("len=%d cap=%d slice=%v\n",len(sli[:len(sli)-2]),cap(sli[:len(sli)-2]),sli[:len(sli)-2])
14
15 //删除开头 2 个元素
16 fmt.Printf("len=%d cap=%d slice=%v\n",len(sli[2:]),cap(sli[2:]),sli[2:])
17
18 //删除中间 2 个元素
19 sli = append(sli[:3], sli[3+2:]...)
20 fmt.Printf("len=%d cap=%d slice=%v\n",len(sli),cap(sli),sli)
21}
