ES15 / ECMAScript 2025: What’s New in JavaScript? 🎉✨

function checkAnimal(animal) {
    if (animal.type === "dog" && animal.sound === "woof") {
        return "It's a dog! 🐶";
    } else if (animal.type === "cat" && animal.sound === "meow") {
        return "It's a cat! 🐱";
    } else {
        return "Unknown animal 😕";
    }
}

function checkAnimal(animal) {
	return match (animal) {
		{ type: "dog", sound: "woof" } => "It's a dog! 🐶",
		{ type: "cat", sound: "meow" } => "It's a cat! 🐱",
		_=> "Unknown animal 😕"
	};
}

const result = process(clean(parse(inputData)));

const result = inputData
	|> parse
	|> clean
	|> process;

async function fetchData() {
	const response = await apiCall();
	// oops... where did my context go?!
}

async function fetchData() {
	const context = getCurrentContext();
	const response = await apiCall();
	return response;
}

const setA = new Set([1, 2, 3]);
const setB = new Set([3, 4, 5]);
const union = new Set([...setA, ...setB]);

const setA = new Set([1, 2, 3]);
const setB = new Set([3, 4, 5]);
const union = setA.union(setB);

const arr = [1, 4, 2, 3];
const sortedArr = [...arr].sort((a, b) => a - b);

const arr = [1, 4, 2, 3];
const sortedArr = arr.toSorted(); // 원본 배열은 건들지 않음

const date = new Date('2023-12-01');
const nextMonth = new Date(date.setMonth(date.getMonth() + 1));

const date = Temporal.PlainDate.from('2023-12-01');
const nextMonth = date.add({ months: 1 });