如何使用動態鍵獲取數組 object 值的總值

Question

我有以下模擬數組，

這個數組是演示目的，我知道 owlCount 沒有意義。

let arr = [
    {
        "id": "000701",
        "status": "No Source Info",
        "sources": []
    },
    {
        "id": "200101",
        "status": "Good",
        "sources": [
            {
                "center": "H2",
                "uri": "237.0.1.133",
                "owlCount": 1,
                "status": "Good",
                "state": {
                    "authState": "authorized",
                    "lockState": "locked"
                }
            }
        ]
    },
    {
        "id": "005306",
        "status": "Good",
        "sources": [
            {
                "center": "H1",
                "uri": "237.0.6.5",
                "owlCount": 3,
                "status": "Good",
                "state": {
                    "authState": "authorized",
                    "lockState": "locked"
                }
            },
            {
                "center": "H1",
                "uri": "237.0.6.25",
                "owlCount": 5,
                "status": "Good",
                "state": {
                    "authState": "authorized",
                    "lockState": "locked"
                }
            }
        ]
    }
]

我將如何 go 關於使用 reduce 在每個嵌套數組中添加值owlCount 。 無需執行[0]即可進入嵌套數組

我在想這樣的事情，但我得到的值為 0，而它應該是 9

const sum = arr.reduce( (acc, cv, i) => {
    acc[i] += cv.owlCount
return acc
}, 0)

我做錯了什么，應該有什么解決方案。

Answer 1

這里的acc是一個數字而不是一個數組，不知道你為什么要使用 acc[i]？ 您必須在這里運行兩個 reduce 循環。 一個用於外部數組，一個用於內部數組，以從源中獲取 owlCount 的總和。

 let arr = [ { "id": "000701", "status": "No Source Info", "sources": [] }, { "id": "200101", "status": "Good", "sources": [ { "center": "H2", "uri": "237.0.1.133", "owlCount": 1, "status": "Good", "state": { "authState": "authorized", "lockState": "locked" } } ] }, { "id": "005306", "status": "Good", "sources": [ { "center": "H1", "uri": "237.0.6.5", "owlCount": 3, "status": "Good", "state": { "authState": "authorized", "lockState": "locked" } }, { "center": "H1", "uri": "237.0.6.25", "owlCount": 5, "status": "Good", "state": { "authState": "authorized", "lockState": "locked" } } ] } ] const sum = arr.reduce( (acc, item) => { return acc += item.sources.reduce((a,source) => a += source.owlCount,0) }, 0) console.log(sum);