Multi tool use

Parameter that's a list of interface{} [duplicate]

This question already has an answer here:

I'm trying to create a function that prints out the len of a list passed into it, regardless of the type of the list. My naive way of doing this was:

len

func printLength(lis interface{}) {
fmt.Printf("Length: %d", len(lis))
}


However, when trying to use it via

func main() {
strs := string{"Hello,", "World!"}
printLength(strs)
}


It complains saying

cannot use strs (type string) as type interface {} in argument to printLength


But, a string can be used as a interface{}, so why can't a string be used as a interface{}?

string

interface{}

string

interface{}

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for

fmt.Printf()

1 Answer
1

You can use reflect package - playground

import (
"fmt"
"reflect"
)
func printLength(lis interface{}) {
fmt.Printf("Length: %d", reflect.ValueOf(lis).Len())
}