开始-如何检查类型相等性？

Question

Say I have the following code:

var x interface{}
y := 4
x = y
fmt.Println(reflect.TypeOf(x))

This will print int as the type. My question is how can I test for the type? I know there is the type switch which does this, so I could do:

switch x.(type) {
case int:
    fmt.Println("This is an int")
}

But if I only want to check for just one specific type the switch seems like the wrong tool. Is there a more direct method of doing this like

reflect.TypeOf(x) == int

or is the type switch the way to go?

Answer 1

Type assertions return two values .. the first is the converted value, the second is a bool indicating if the type assertion worked properly.

So you could do this:

_, ok := x.(int)

if ok {
    fmt.Println("Its an int")
} else {
    fmt.Println("Its NOT an int")
}

..or, shorthand:

if _, ok := x.(int); ok {
    fmt.Println("Its an int")
}

<kbd>See it in the playground</kbd>