Nullish

code:javascript

// Nullish Coalescing

// check whether left-hand is null or undefined

const hoge = null ?? "default"; // "default"

const fuga = false ?? "default"; // false

// Optional Chaining

// check whether obj ref is nullish

obj = {

fuga: "fuga",

};

obj?.hoge; // undefined

obj && obj.hoge; // equal to this statement

obj?.fuga; // "fuga"

obj?.fuga?.hoge; // undefined