随手记录小练习

如下数组，计算value相加的和

const a = [
    {name: 'a', value: 1},
    {name: 'b', value: 2},
    {name: 'c', value: 3},
    {name: 'd', value: 4},
  ]

用forEach写

let sum = 0;
a.forEach(item => {sum += item.value})；
console.log(sum) // 10

用reduce写

let num = a.reduce((a,b) => {return a + b.value},0)
console.log(num) // 10

计算这个数组value不是1的其他数组的和

const oneArr = a.filter(item => item.value != 1);
oneArr.reduce((a, b) => {return a + b.value}, 0); // 9