检查指针是否指向 Nil Slice

Question

我有一个函数，它接受指向任何切片的指针，并且所述参数的类型为interface{}。我需要确保指针不指向切片nil。package mainimport (    "fmt")type Dog struct {    Name string    Age  int}func main() {    var slicePointer interface{}    // We only want slices that were initialized with `make()`.    dogs1 := make([]Dog, 0)    fmt.Println("dogs1 == nil:", dogs1 == nil)    slicePointer = &dogs1    fmt.Println("slicePointer == nil:", slicePointer == nil)    fmt.Println("-----")    // This needs to be caught, as the slice is `nil`.    var dogs2 []Dog    fmt.Println("dogs2 == nil:", dogs2 == nil)    slicePointer = &dogs2    fmt.Println("slicePointer == nil:", slicePointer == nil)}输出：dogs1 == nil: falseslicePointer == nil: false-----dogs2 == nil: trueslicePointer == nil: false   有没有办法在 Golang 中进行这样的检查？

Answer 1

您可以使用反射判断非 nil 接口是否具有 nil 指针值：

fmt.Println(reflect.ValueOf(slicePointer).Elem().IsNil())

最安全的方法：

  if slicePointer!=nil {

    v:=reflect.ValueOf(slicePointer)

    if v.Kind()==reflect.Ptr {

      fmt.Println(v.Elem().IsNil())

    }

  }