Go切片的操作

package main

import "fmt"

//切片的操作

func main() {

    //创建slice
    var s []int  //zero value for slice is nil

    for i := 0; i < 10; i++ {
        s = append(s, 2 * i + 1)
    }
    fmt.Println(s)  //[1 3 5 7 9 11 13 15 17 19]

    s1 := []int{2, 4, 6, 8}
    fmt.Println(s1)  //[2 4 6 8]
    fmt.Printf("cap:%d
", cap(s1)) //cap:4

    s2 := make( []int, 16)
    fmt.Println(s2)  //[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]
    fmt.Printf("cap:%d
", cap(s2))  //cap:16

    s3 := make( []int, 10, 32)  //32设置的是cap值
    fmt.Println(s3)   //[0 0 0 0 0 0 0 0 0 0]
    fmt.Printf("cap:%d
", cap(s3))  //cap:32

    //复制slice
    copy(s2, s1)
    fmt.Println(s2,len(s2), cap(s2))  //[2 4 6 8 0 0 0 0 0 0 0 0 0 0 0 0] 16 16

    //删除slice中的元素
    s2 = append( s2[:3], s2[4:]...)
    fmt.Println(s2, len(s2), cap(s2))  //[2 4 6 0 0 0 0 0 0 0 0 0 0 0 0] 15 16

    front := s2[0]
    s2 = s2[1:]
    fmt.Println(front)  //2
    fmt.Println(s2, len(s2), cap(s2))    //[4 6 0 0 0 0 0 0 0 0 0 0 0 0] 14 15

    tail := s2[len(s2) - 1]
    s2 = s2[: len(s2) - 1]
    fmt.Println(tail)  //0
    fmt.Println(s2, len(s2), cap(s2))   //[4 6 0 0 0 0 0 0 0 0 0 0 0]  13 15

}