JSFiddle - React, Tailwind, and code Playground

JavaScript

var functions = {
    'alert':'alert', 
    'undefinedFunction':'undefinedFunction', 
    'ff.showAlert':'ff.showAlert'
};

var ff = {
    showAlert: function() {
        alert('the function works');
    }
};

for (i in functions) {
    console.log(i+' : '+typeof window[functions [i]]);
}
console.log(typeof window.ff.showAlert);