Type of function parameter changes

[Amarjeet Anand]

Hi

Why does the type of a parameter passed to another function changes?

For example: 

func P(args ...interface{}) {
   print("\n", args)
}

func print(seperator string, args ...interface{}) {
   for _, arg := range args {
      fmt.Println("arg type: ", reflect.TypeOf(arg))

      str := ""
      switch v := arg.(type) {
      case byte:
         str = string(v)
      case rune:
         str = string(v)
      case int:
         str = strconv.Itoa(v)
      case int64:
         str = strconv.FormatInt(v, 10)
      case string:
         str = v
      }
      out.WriteString(str + seperator)
   }
}

Calling P("one"[2]) gives type as  []interface {}

where as directly calling print("one"[2]) gives type as byte

Why is it like this? 

And any way i can achieve this without putting switch in P() function?

[Jesse McNelis]

Hi,

You can simply do:

func P(args ...interface{}) {
   print("\n", args...)
}

The problem you encountered was that you were passing the args as a single argument to print()

The 'var args' syntax collects the arguments and puts them in a slice. So args in P() is a []interface{}.

You then pass that whole []interface{} as an argument to print(), for args in print() gets a []interface{} where the first item in the slice is an interface{} that contains a []interface{}, which isn't what you wanted.

By using the spread operator when passing the args slice to print(), you get the pass the args slices multiple arguments to print().

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[Amarjeet Anand]

Hi Jesse

Thanks for the response. 

Got it.