index.js

function ajaxCall(){
  $.ajax({
        url: 'https://en.wikipedia.org/w/api.php?action=query&list=search&format=json&srsearch=' + $('#search').val(),
        dataType: 'jsonp',
        type: 'GET',
        success: function(data) {
            // console.log(data);
            $('#update').empty();
            var data = JSON.stringify(data);
            data = JSON.parse(data);
            //console.log(data.query.search);
            // loop through data and output
            var output = '';
            data.query.search.forEach(function(data) {
                var title = '<h2>' + data.title + '</h2>' + '<br>';
                var snippet = '<p>' + data.snippet + '</P>';
                var url = '<a href="https://en.wikipedia.org/wiki/' + data.title + '" target="_blank">';
                var endUrl = '</a>';
                output += url + title + endUrl + snippet + '<hr>';
            });
            $('#update').append(output);
        }
    });
}

function randomFunction(){
  $('#update').empty();
  $('#search').empty();
  $('iframe').attr('src','https://en.wikipedia.org/wiki/Special:Random');
}
$(document).ready(function(){
  $('#search').focus();
  $('#search').off('keyup');
  $('#search').on('keyup',function(){
    ajaxCall();
    $('iframe').attr('src','');
  });
  //show random wiki Article
  $('.random').on('click',function(){
    randomFunction();
    $(this).text('Show me another random article!');
  });
});