Typeof.md

Finding the type of an object

There is the typeof in C; there is typeof in JavaScript; and there is type() in Python to see what type has an object.

In Go, there is not typeof, nor type in the basic syntax, but there are three ways to get an object's type:

1. String formatting

The simplest way.

n := 3.14
fmt.Printf("%T", n)
// float64

2. Type assertion

We have to prepare it a little bit:

1. Use .(type) inside type switch.
2. Type switch can be done on an interface value only.

var n interface{}
n = 3.14
switch n.(type) {
    case int:
        fmt.Println("int")
    case float32:
        fmt.Println("float32")
    case float64:
        fmt.Println("float64")
    default:
        fmt.Println("unknown")
}
// float64

3. Reflect package's TypeOf()

An import is needed from the standard library. Here is that we missed in the basic syntax. :)

import "reflect"  // outside in the import section

n := 3.14
fmt.Println(reflect.TypeOf(n).String())
// float64

Based on Stacoverflow comment of Grzegorz Luczywo.