iterator.md

迭代器

• 使用高阶函数例如map()和 reduce()替代 for-of

const numbers = [1, 2, 3, 4, 5];

// bad
let sum = 0;
for (let num of numbers) {
    sum += num;
}

sum === 15;

// good
let sum = 0;
numbers.forEach((num) => sum += num);
sum === 15;

// best (use the functional force)
const sum = numbers.reduce((total, num) => total + num, 0);
sum === 15;