102-optional-chaining.md

title	description	weight	lastmod	draft	vimeo	emoji	video_length	quiz
Optional Chaining	Call object properties safely	23	2022-11-11 10:23:30 -0900	false	773489916	⛓	6360	true

What is the return value when calling a property that does not exist with optional chaining?

Optional Chaining

Optional chaining ? is a relatively new operator that was introduced in ES2020. It allows you to call object properties safely, without throwing an error. When calling properties without this operator, you many crash your applcation with the error Cannot read property 'foo' of undefined.

const person = { };

const dude = person.name;
console.log(foo); // Uncaught TypeError: Cannot read property 'bar' of undefined

const dude = person?.name; // undefined