[JavaScript] ES2020のconst, let, var

strict

'use strict'; // 厳密なエラーチェック

定数 // 再代入不可

		const price = 10;
		console.log(price * 3);

変数 // letを使う　varは古い書き方

		let price = 10;
		price = 30;
		console.log(price * 3);

無名関数

const sum = function(a, b, c){
			return a + b + c;
		}
		const total = sum(1, 2, 3) + sum(4, 5, 6);
		console.log(total);

arrow function

const sum = (a, b, c) => a + b + c;