golang append坑

查看如下代码输出

package mainimport "fmt"func main() {a := make([][]int, 0)b := make([]int, 0)b = append(b, 1)a = append(a, b)fmt.Println(a)b[0] = 2fmt.Println(a)
}

输出：

[[1]]
[[2]]

可以看出b改变之后，在a中也发生了改变，可以如下修改

package mainimport "fmt"func main() {a := make([][]int, 0)b := make([]int, 0)b = append(b, 1)tmp := make([]int, 1)copy(tmp, b)a = append(a, tmp)fmt.Println(a)b[0] = 2fmt.Println(a)
}

输出

[[1]]
[[1]]