Return nested object property.js

function myFunction(obj = {}) {


 // return Object.getOwnPropertyNames(obj).join('') === 'a' ? obj.a.b : undefined
    return obj?.a?.b;
}


// console.log(myFunction({ a: { b: { c: 3 } } }));
// console.log(myFunction({a:1}));
// console.log(myFunction({b:{a:1}}));
console.log(myFunction({a:{b:2}}));