Answers for "the ?. in js"

~~ in javascript

~~ used to convert some types to int (32 bit int)

what is ... in javascript

function sum(...numbers) {
	return numbers.reduce((accumulator, current) => {
		return accumulator += current;
	});
};
 
sum(1,2) // 3
sum(1,2,3,4,5) // 15

~~ in javascript

~~'-1' = -1
~~true = 1
~~false = 0
~~5.6 = 5