Untitled

var arr = ['Afghanistan',
'Albania',
'Algeria',
'Andorra',
'Angola',
'Antigua and Barbuda',
'Argentina',
'Armenia',
'Australia',
'Austria',
'Azerbaijan',
'Bahamas',
'Bahrain',
'Bangladesh',
'Barbados',
'Belarus',
'Belgium',
'Belize',
'Benin',
'Bhutan',
'Bolivia',
'Bosnia and Herzegovina',
'Botswana',
'Brazil',
'Brunei',
'Bulgaria',
'Burkina',
'Burundi',
'Cambodia',
'Cameroon',
'Canada',
'Cape Verde',
'Central African Republic',
'Chad',
'Chile',
'China',
'Colombia',
'Comoros',
'Costa Rica',
'Croatia',
'Cuba',
'Cyprus',
'Czech Republic',
'Denmark',
'Djibouti',
'Dominica',
'Dominican Republic',
'East Timor',
'Ecuador',
'Egypt',
'El Salvador',
'Equatorial Guinea',
'Eritrea',
'Estonia',
'Ethiopia',
'Fiji',
'Finland',
'France',
'Gabon',
'Gambia',
'Georgia',
'Germany',
'Ghana',
'Greece',
'Grenada',
'Guatemala',
'Guinea',
'Guinea-Bissau',
'Guyana',
'Haiti',
'Honduras',
'Hungary',
'Iceland',
'India',
'Indonesia',
'Iran',
'Iraq',
'Ireland',
'Israel',
'Italy',
'Ivory Coast',
'Jamaica',
'Japan',
'Jordan',
'Kazakhstan',
'Kenya',
'Kiribati',
'North Korea',
'South Korea',
'Kosovo',
'Kuwait',
'Kyrgyzstan',
'Laos',
'Latvia',
'Lebanon',
'Lesotho',
'Liberia',
'Libya',
'Liechtenstein',
'Lithuania',
'Luxembourg',
'Macedonia',
'Madagascar',
'Malawi',
'Malaysia',
'Maldives',
'Mali',
'Malta',
'Marshall Islands',
'Mauritania',
'Mauritius',
'Mexico',
'Moldova',
'Monaco',
'Mongolia',
'Montenegro',
'Morocco',
'Mozambique',
'Myanmar',
'Namibia',
'Nauru',
'Nepal',
'Netherlands',
'New Zealand',
'Nicaragua',
'Niger',
'Nigeria',
'Norway',
'Oman',
'Pakistan',
'Palau',
'Panama',
'Papua New Guinea',
'Paraguay',
'Peru',
'Philippines',
'Poland',
'Portugal',
'Qatar',
'Romania',
'Russia',
'Rwanda',
'St Kitts & Nevis',
'St Lucia',
'Saint Vincent & the Grenadines',
'Samoa',
'San Marino',
'Sao Tome & Principe',
'Saudi Arabia',
'Senegal',
'Serbia',
'Seychelles',
'Sierra Leone',
'Singapore',
'Slovakia',
'Slovenia',
'Solomon Islands',
'Somalia',
'South Africa',
'South Sudan',
'Spain',
'Sri Lanka',
'Sudan',
'Suriname',
'Swaziland',
'Sweden',
'Switzerland',
'Syria',
'Taiwan',
'Tajikistan',
'Tanzania',
'Thailand',
'Togo',
'Tonga',
'Trinidad & Tobago',
'Tunisia',
'Turkey',
'Turkmenistan',
'Tuvalu',
'Uganda',
'Ukraine',
'United Arab Emirates',
'United Kingdom',
'United States',
'Uruguay',
'Uzbekistan',
'Vanuatu',
'Vatican City',
'Venezuela',
'Vietnam',
'Yemen',
'Zambia',
'Zimbabwe'];

var num = Math.floor(Math.random() * (196 - 0)) + 0;
var country = 'images/' + arr[num] + '.png';
$("#img").attr("src","country");

<!DOCTYPE html>
<html>
<head>
    <title>Flags game</title>
    <link rel="stylesheet" href="css/style.css">
    <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>

</head>
<body>


    <h1>GTF</h1>


        <img id="img" src="images/Russia.png" alt="">

    <input type="text" id="test">

    <input type="button" value="Check" id="xe">
    </div>
    </div>
    <script src="js/script.js"></script>

</body>
</html>

var arr = ['Afghanistan', 'Albania', 'Serbia', 'Yemen', 'Zambia','Zimbabwe'];

var rand = Math.floor(Math.random() * arr.length);
var country = 'images/' + arr[rand] + '.png';

$("#img").attr("src", "country");