计算对象数组中的重复项并对位于对象中的值求和

我有一个看起来像这样的对象数组：

const users = [{name: 'John', gender: 'Male', orders: 20},
    {name: 'Doe', gender: 'Male', orders: 8},
    {name: 'Ada', gender: 'Female', orders: 10},
    {name: 'David', gender: 'Male', orders: 30}];

我需要计算重复性别的数量，并根据对象中的性别总结订单数量。我希望最终的数组如下所示：

[{gender: 'Male', count: 3, totalOrders: 58}, {gender: 'Female', count: 1, totalOrders: 10}]

这是我到目前为止的代码：

const usersGender = users.map((user) => user.gender);

const result = Object.values(usersGender.reduce((a, b) => {
  a[b] = a[b] || [b, 0];
  a[b][1]++;
  return a;
},{})).map(item => ({gender: item[0], count : item[1]}));

console.log(result);

我上面代码的输出是：

[{ gender: 'Male', count: 3 }, { gender: 'Female', count: 1 }]

谢谢你。

回答

const
    users = [{ name: 'John', gender: 'Male', orders: 20 }, { name: 'Doe', gender: 'Male', orders: 8 }, { name: 'Ada', gender: 'Female', orders: 10 }, { name: 'David', gender: 'Male', orders: 30 }],
    result = Object.values(users.reduce((r, { gender, orders }) => {
        r[gender] ??= { gender, count: 0, totalOrders: 0 };
        r[gender].count++;
        r[gender].totalOrders += orders;
        return r;
    }, {}));

console.log(result);

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