Initialize array of interfaces in Golang

Question

Here is an example of variable:

names := []interface{}{"first", "second"}

How can it be initialized dynamically, from an array of strings?

Answer 1

strs := []string{"first", "second"}
names := make([]interface{}, len(strs))
for i, s := range strs {
    names[i] = s
}

Would be the simplest

Answer 2

append initializes slices, if needed, so this method works:

var names []interface{}
names = append(names, "first")
names = append(names, "second")

And here is a variation of the same thing, passing more arguments to append:

var names []interface{}
names = append(names, "first", "second")

This one-liner also works:

names := append(make([]interface{}, 0), "first", "second")

---

It's also possible to convert the slice of strings to be added to a slice of interface{} first.

Answer 3

You can use interface{} array to build it.

values := make([]interface{}, 0)
values = append(values, 1, 2, 3, nil, 4, "ok")

Then check the type when using the value.

for _, v := range values {
    if v == nil {
        fmt.Println("it is a nil")
    } else {
        switch v.(type) {
        case int:
            fmt.Println("it is a int")
        case string:
            fmt.Println("it is a string")
        default:
            fmt.Println("i don't know it")
        }
    }
}