What will the code below output to the console and why?

[HarleyKelvin]

(function(){
var a = b = 3;
})();

console.log("a defined? " + (typeof a !== 'undefined'));
console.log("b defined? " + (typeof b !== 'undefined'));

[A_AhkUser]

see: https://www.w3schools.com/js/js_scope.asp