package main

import "fmt"

func main() {

    fmt.Println("为切片动态添加元素")
    var a []int
    a = append(a, 1)                 //追加一个元素
    a = append(a, 2, 3, 4)           //追加一组元素
    a = append(a, []int{5, 6, 7}...) //追加一个切片, 切片需要解包

    for k, v := range a {
        fmt.Printf("%d %d \n", k, v)
    }
    fmt.Println("在切片的开头添加元素")
    var b = []int{1, 2, 3}
    b = append([]int{0}, b...)      //在开头添加1个元素
    b = append([]int{-2, -1}, b...) //在开关添加1个切片
    for k, v := range b {
        fmt.Printf("%d %d \n", k, v)
    }
}