Function isFunction

static/bootstrap4/js/bootstrap.bundle.js:1587–1590

* Check if the given variable is a function * @method * @memberof Popper.Utils * @argument {Any} functionToCheck - variable to check * @returns {Boolean} answer to: is a function?

(functionToCheck)

   * @returns {Boolean} answer to: is a function?
   */
  function isFunction(functionToCheck) {
    var getType = {};
    return functionToCheck && getType.toString.call(functionToCheck) === '[object Function]';
  }

  /**
   * Get CSS computed property of the given element