数组去重和求和

文章来源

zhuanlan.zhihu.com/p/54758068

Set 与去重

• 数组去重

const arr = [3, 5, 2, 2, 5, 5];
const unique = [...new Set(arr)];

• 数组去重函数

function unique(array) {
  return [...new Set(array)];
}

• 字符去重

let str = [...new Set("ababbc")].join("");
console.log(str);

数组求和

let foo = [1, 2, 3, 4, 5];

//不优雅
function sum(arr) {
  let x = 0;
  for (let i = 0; i < arr.length; i++) {
    x += arr[i];
  }
  return x;
}
sum(foo); // => 15

//优雅
foo.reduce((a, b) => a + b); // => 15