如何根据我发送到Go中的函数的变量返回特定类型的切片

Question

I have a function, that takes an empty interface (any type, which im looking for 2 in specific) and then returning a slice of the selected type.

func testingInterface(temp interface{}) (interface{}, interface{}) {
var doc interface{}

array := make([]interface{}, 3)

switch x := temp.(type) {
case int:
    doc = x
    tempArray := make([]string, 3)
    for i, v := range tempArray {
        array[i] = string(v)
    }
    fmt.Printf("Int to string %T, %T ", doc, tempArray)
case string:
    doc = x
    tempArray := make([]int, 3)

    for i, v := range tempArray {
        array[i] = int(v)
    }
    fmt.Printf("String to int %T, %T ", doc, tempArray)
}

  return array, doc
}

So what happens, it is that the doc variable indeed changes the type of it, but the slice when i return it, it stays as []interface{} When i test an element individual, it changes the type but the whole array it is still an []interface{}

Answer 1

The tempArray in the question has the slice you want. Return it instead of copying the values to the []interface{} that you don't want.

Use this code:

func testingInterface(x interface{}) (interface{}, interface{}) {
    var result interface{}
    switch x.(type) {
    case int:
        result = make([]int, 3)
    case string:
        result = make([]string, 3)
    }
    return result, x
}