There are some situations where you won't be sure what type a variable is when it is returned from a function. You can always check a variable's type by using var.(type)
if you are unsure what type it is:
x := someFunction() // Some value of an unknown type is stored in x now
switch x := x.(type) {
case bool:
fmt.Printf("boolean %t\n", x) // x has type bool
case int:
fmt.Printf("integer %d\n", x) // x has type int
case string:
fmt.Printf("pointer to boolean %s\n", x) // x has type string
default:
fmt.Printf("unexpected type %T\n", x) // %T prints whatever type x is
}