drba1172 2017-02-20 19:00
浏览 124
已采纳

Golang slice附加内置函数返回值

The return value of slice2 of this code is [[1 1][1 1]].
And that got me confuse because I was expecting [[0 0][1 1]].
I can't figure it out why is returning [[1 1][1 1]] and not [[0 0][1 1]].
I would appreciate if someone can explain that. Thanks.

slice := []int{0, 0}
slice2 := [][]int{}

for i := range slice {
    slice[0] = i
    slice[1] = i
    slice2 = append(slice2, slice)
}
fmt.Println(slice2)

You can check the code in this link play.golang.org

  • 写回答

3条回答 默认 最新

  • dongmei8071 2017-02-20 19:36
    关注

    A slice is a descriptor of an array segment. It consists of a pointer to the array, the length of the segment, and its capacity (the maximum length of the segment).

    In your case your are appending a slice(pointer) not the slice's values. To get the desired result you have to declare a new slice in each iteration and append the new slice to slice2.

    func main() {
        slice := []int{0, 0}
        slice2 := [][]int{}
    
        for i := range slice {
            ns := []int{0, 0}
            ns[0] = i
            ns[1] = i
            slice2 = append(slice2, ns)
        }
        fmt.Println(slice2) // Outputs: [[0 0] [1 1]]
    }
    

    Playground

    本回答被题主选为最佳回答 , 对您是否有帮助呢?
    评论
查看更多回答(2条)

报告相同问题?

悬赏问题

  • ¥15 java 判断某个数 区间是否存在
  • ¥15 appium控制多个雷电模拟器问题
  • ¥15 C# iMobileDevice
  • ¥15 谁会做这个啊#ensp#Boson NetSim
  • ¥15 如何编写针对TPS6503320FRGE型号的电源管理芯片的编程代码?
  • ¥15 设计简单目录管理系统,要满足以下内容
  • ¥15 关于九十度混合耦合器信号分析问题
  • ¥15 Cesm如何关闭不用的模块呢
  • ¥15 vue2两层数据导出为excle
  • ¥15 有人能帮我做一下这个项目吗