When you have an `interface{}` (or any) and need to dispatch on its underlying type, use `switch v := x.(type)`. Cleaner than a chain of type-assertions.
Go
package main
import "fmt"
func describe(x any) string {
switch v := x.(type) {
case int:
return fmt.Sprintf("int %d", v)
case string:
return fmt.Sprintf("string of length %d: %q", len(v), v)
case bool:
return fmt.Sprintf("bool: %t", v)
case []int:
return fmt.Sprintf("[]int with %d elements", len(v))
case nil:
return "nil"
default:
return fmt.Sprintf("unknown type %T", v)
}
}
func main() {
for _, x := range []any{42, "hello", true, []int{1, 2, 3}, 3.14, nil} {
fmt.Println(describe(x))
}
}Save your own code snippets
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