【javascript】ES6(ES2015) Array ループメソッド - Qiita

let nums = [1, 2, 3] let sum = 0; let idx = []; let ary = []; nums.forEach((item, index, array) => { sum += item; idx.push(index); ary.push(array); }) sum // => 6 idx // => [0,1,2] ary // => [[1,2,3],[1,2,3],[1,2,3]] let products = [ { "name": "apple", "number": 100, "price": 300 }, { "name": "orange", "number": 60, "price": 150 }, { "name": "peach", "number": 250, "price": 400 } ]; let sales = []