• 使用set对象给数组去重
  [...new Set(array)]

• 字符串数组转数字数组
  ['1', '2', '3'].map(Number); // [1, 2, 3]

• 构造数组
  Array(5).fill().map((_,i) => i+1); // [1, 2, 3, 4, 5]

• 数组求和第一弹

function addUp() {
  let total = 0;
  for(let num of arguments) {
    total += num;
  }
  return total;
}

addUp(1, 2, 3, 4);  // 10

• 数组求和第二弹

function addUp() {
  const nums = Array.from(arguments);
  return nums.reduce((prev, next) => prev + next, 0)
}

addUp(1, 2, 3, 4);  // 10

• 类数组转数组

<div class="people">
  <p>Jay</p>
  <p>Eason</p>
  <p>David</p>
</div>

const people  = Array.from(document.querySelectAll('.people p'));
const names = people.map(person => person.textContent);
console.log(names);  // ['Jay', 'Eason', 'David']