如何获得具有唯一值的对象数组？

Question

如何对具有相同键值的对象数组求和？

我有这个数组：

let arrData = [{ category: "Main Expenses", amount: 420 },
    { category: "Food", amount: 50 },
    { category: "Main Expenses", amount: 4530},
    { category: "Food", amount: 4520 },
    { category: "Main Expenses", amount: 4530 },
    { category: "Food", amount: 450 },
    { category: "Self Care", amount: 7540 },
    { category: "Child Care", amount: 4570 }]

我需要获得具有唯一类别的数组，如下所示：

[Main Expenses: 9480,
Food: 5020,
Self Care: 7540,
Child Care: 4570]

Answer 1

由于数组不支持键值对，因此无法在数组中获得预期的输出。 您可以选择对象。

您可以使用reduce并按类别名称检查对象是否包含key 。 如果是这样，则添加金额，否则按类别名称创建键并将其值设置为金额

 let arrData = [{ category: "Main Expenses", amount: 420 }, { category: "Food", amount: 50 }, { category: "Main Expenses", amount: 4530 }, { category: "Food", amount: 4520 }, { category: "Main Expenses", amount: 4530 }, { category: "Food", amount: 450 }, { category: "Self Care", amount: 7540 }, { category: "Child Care", amount: 4570 } ] let newData = arrData.reduce((acc, item) => { acc[item.category] = acc[item.category] ? acc[item.category] + item.amount : item.amount; return acc; }, {}); console.log(newData)