Get Bootstrap Version

bootstrap_version_utility.js

var getBootstrapVersion = function () {
  var deferred = $.Deferred();

  var script = $('script[src*="bootstrap"]');
  if (script.length == 0) {
    return deferred.reject();
  }

  var src = script.attr('src');
  $.get(src).done(function(response) {
    var matches = response.match(/(?!v)([.\d]+[.\d])/);
    if (matches && matches.length > 0) {
      version = matches[0];
      deferred.resolve(version);
    }
  });

  return deferred;
};

getBootstrapVersion().done(function(version) {
  console.log(version); // '3.3.5'
});