i need to do optional function. How can i do like this:
console.log(db.(x==true ? input(...) : ["no function"]).query(...));
// if x is true console.log(db.input(...).query(...));
// if x is false console.log(db.query(...));
You don't need to compare x with true:
console.log((x ? db.input(...) : db).query(...));
You want to call query either on db or on db.input(...) depending on x.
Example:
const db = { input() { return { query() { return 'db.input(...).query(...)'; } } }, query() { return 'db.query(...)'; } };
console.log((true ? db.input() : db).query());
console.log((false ? db.input() : db).query());console.log(x === true? db.input(...).query(...) : db.query(...))