javascript - 返回 Object.map 中的键未定义

Question

我下面的循环有什么问题？我想计算total_count并在 map 中进行一些操作后返回[total,total]，但我没有定义。

我的原始数据

const raw = [{
  "device_info": {
    "name": "cam1",
  },
  "age_range": {
    "0-10": {
      "age_range": "0-10",
      "total_count": 15,
      "male_count": 6,
      "female_count": 9
    },
    "11-20": {
      "age_range": "11-20",
      "total_count": 11,
      "male_count": 7,
      "female_count": 4
    },
    "21-30": {
      "age_range": "21-30",
      "total_count": 922,
      "male_count": 452,
      "female_count": 470
    }
  }
}, {
  "device_info": {
    "name": "cam2",
  },
  "age_range": {
    "0-10": {
      "age_range": "0-10",
      "total_count": 1,
      "male_count": 1,
      "female_count": 0
    },
    "11-20": {
      "age_range": "11-20",
      "total_count": 2,
      "male_count": 0,
      "female_count": 2
    },
    "21-30": {
      "age_range": "21-30",
      "total_count": 90,
      "male_count": 58,
      "female_count": 32
    }
  }
}]

循环

const x = raw.map(obj => {
  return Object.keys(obj).forEach(key => {
    let total = 0
    if (key === 'age_range') {
      total = Object.keys(obj.age_range).reduce((acum, innerKey) => {
        return acum + obj.age_range[innerKey].total_count
      }, 0)
      console.log(total)
    }
  });
})

console.log('x', x)

https://jsfiddle.net/19m3f7fs/1

Answer 1

Array#forEach 不返回任何内容，请使用 Array#map和 Object.values相反:

const x = raw.map(obj => {
  return Object.values(obj.age_range).reduce((acc, item) => acc + item.total_count, 0)
})

工作示例:

const raw = [{
  "device_info": {
    "name": "cam1",
  },
  "age_range": {
    "0-10": {
      "age_range": "0-10",
      "total_count": 15,
      "male_count": 6,
      "female_count": 9
    },
    "11-20": {
      "age_range": "11-20",
      "total_count": 11,
      "male_count": 7,
      "female_count": 4
    },
    "21-30": {
      "age_range": "21-30",
      "total_count": 922,
      "male_count": 452,
      "female_count": 470
    }
  }
}, {
  "device_info": {
    "name": "cam2",
  },
  "age_range": {
    "0-10": {
      "age_range": "0-10",
      "total_count": 1,
      "male_count": 1,
      "female_count": 0
    },
    "11-20": {
      "age_range": "11-20",
      "total_count": 2,
      "male_count": 0,
      "female_count": 2
    },
    "21-30": {
      "age_range": "21-30",
      "total_count": 90,
      "male_count": 58,
      "female_count": 32
    }
  }
}]

const x = raw.map(obj => Object.values(obj.age_range).reduce((acc, item) => acc + item.total_count, 0))

console.log(x)