Using a jQuery's $.each

each.js

$.ajax({
  url: 'http://api.randomuser.me/?results=10',
  dataType: 'json',
  success: function(data) {
    addUsername(data);
  }
});

addUsername = function(data) {
  $.each(data.results, function(i) {
    $('body').append('<p>' + data.results[i].user.name.first + ' ' + data.results[i].user.name.last + '</p>');
  });
};