鍵入開關

Created: November-22, 2018

型別開關也可用於獲取與案例型別匹配的變數：

func convint(v interface{}) (int,error) {
    switch u := v.(type) {
    case int:
        return u, nil
    case float64:
        return int(u), nil
    case string:
        return strconv(u)
    default:
        return 0, errors.New("Unsupported type")
    }
}