JSFiddle - React, Tailwind, and code Playground

JavaScript

function a(){}

function b(){
    return;
}

function c(){
    return undefined;
}

document.write('typeof b() ' + (typeof b()));
document.write('<br/>');
document.write('a() === b() '+ (a() === b()));
document.write('<br/>');
document.write('b() === c() '+ (b() === c()));