Javascript 如何使用 reduce 从嵌套对象中获取属性值的总和？

Question

我有一个如下所示的对象：data_sample = {  "object_1": {    "irrelevant_data1": 0,    "irrelevant_data2": 0,    "data_needed_to_sum_up": 100,  },  "object_a": {    "irrelevant_data1": 0,    "irrelevant_data2": 0,    "irrelevant_data3": 0,    "data_needed_to_sum_up": 200,  },  "object_d": {    "irrelevant_data1": 0,    "irrelevant_data2": 0,    "data_needed_to_sum_up": 300,  },}我如何使用该reduce方法获取sumall data_needed_to_sum_upinsidedata_sample以获得预期结果 600？

Answer 1

你可以使用Object.values然后使用reduce

data_sample = { "object_1": { "irrelevant_data1": 0, "irrelevant_data2": 0, "data_needed_to_sum_up": 100, }, "object_a": { "irrelevant_data1": 0, "irrelevant_data2": 0, "irrelevant_data3": 0, "data_needed_to_sum_up": 200, }, "object_d": { "irrelevant_data1": 0, "irrelevant_data2": 0, "data_needed_to_sum_up": 300, }, }

res = Object.values(data_sample)

    .reduce((acc,curr) => acc = acc + curr["data_needed_to_sum_up"],0)

console.log(res)

Answer 2

你可以Array#reduce在Object.values.

let sum = Object.values(data_sample)
         .reduce((acc,cur)=>acc+cur.data_needed_to_sum_up,0);

Answer 3

.reduce适用于数组，您拥有的只是一个对象，但您可以.reduce与 结合使用Object.entries，如下所示：

data_sample = {

  "object_1": {

    "irrelevant_data1": 0,

    "irrelevant_data2": 0,

    "data_needed_to_sum_up": 100,

  },

  "object_a": {

    "irrelevant_data1": 0,

    "irrelevant_data2": 0,

    "irrelevant_data3": 0,

    "data_needed_to_sum_up": 200,

  },

  "object_d": {

    "irrelevant_data1": 0,

    "irrelevant_data2": 0,

    "data_needed_to_sum_up": 300,

  },

}

console.log(Object.entries(data_sample).reduce((carry, [_, current]) => carry + current.data_needed_to_sum_up, 0))

Answer 4

尝试这个：

console.log(Object.values(data_sample).map((x) => x.data_needed_to_sum_up).reduce((x, y) => x + y));

Answer 5

先使用 Object.valuesto 然后使用 reduce