オブジェクトの各プロパティは異なる国コードである：

```js
const countries = {
  "AF": "Afghanistan",
  "AX": "\u00c5land Islands",
  "AL": "Albania",
  "DZ": "Algeria",
  "AS": "American Samoa",
  "AD": "Andorra",
  "AO": "Angola",
  "AI": "Anguilla",
  "AQ": "Antarctica",
  "AG": "Antigua and Barbuda",
  "AR": "Argentina",
  "AM": "Armenia",
  "AW": "Aruba",
  "AU": "Australia",
  "AT": "Austria",
  "AZ": "Azerbaijan",
  "BS": "Bahamas",
  "BH": "Bahrain",
  "BD": "Bangladesh",
  "BB": "Barbados",
  "BY": "Belarus",
  "BE": "Belgium",
  "BZ": "Belize",
  "BJ": "Benin",
  "BM": "Bermuda",
  "BT": "Bhutan",
  "BO": "Bolivia",
  "BA": "Bosnia and Herzegovina",
  "BW": "Botswana",
  "BV": "Bouvet Island",
  "BR": "Brazil",
  "IO": "British Indian Ocean Territory",
  "BN": "Brunei Darussalam",
  "BG": "Bulgaria",
  "BF": "Burkina Faso",
  "BI": "Burundi"
};
```
Sure, here is how that would look in JavaScript as an object, with each property of the object being a different country code:

```js
const countries = {
  "AF": "Afghanistan",
  "AX": "\u00c5land Islands",
  "AL": "Albania",
  "DZ": "Algeria",
  "AS": "American Samoa",
  "AD": "Andorra",
  "AO": "Angola",
  "AI": "Anguilla",
  "AQ": "Antarctica",
  "AG": "Antigua and Barbuda",
  "AR": "Argentina",
  "AM": "Armenia",
  "AW": "Aruba",
  "AU": "Australia",
  "AT": "Austria",
  "AZ": "Azerbaijan",
  "BS": "Bahamas",
  "BH": "Bahrain",
  "BD": "Bangladesh",
  "BB": "Barbados",
  "BY": "Belarus",
  "BE": "Belgium",
  "BZ": "Belize",
  "BJ": "Benin",
  "BM": "Bermuda",
  "BT": "Bhutan",
  "BO": "Bolivia",
  "BA": "Bosnia and Herzegovina",
  "BW": "Botswana",
  "BV": "Bouvet Island",
  "BR": "Brazil",
  "IO": "British Indian Ocean Territory",
  "BN": "Brunei Darussalam",
  "BG": "Bulgaria",
  "BF": "Burkina Faso",
  "BI": "Burundi"
};
```