javascript - 获取 javascript 对象中特定键的总和

Question

我想获取 js 对象中所有 menge 键的总和并将其存储在变量中。有人可以帮助我如何做到这一点吗？我的对象的片段:

var obj = {
  "_15800175": {
    "posID": "159469",
    "scanID": "22597",
    "anr": "15800175",
    "TVanr": "",
    "code": "G-09-27-2E",
    "ean": "4710069680575",
    "marke": "fox",
    "bez": "jersey yellow",
    "bez2": "size xl",
    "menge": "1",
    "ve": "St\u00fcck",
    "Dimensionstext": "TT9857BG\r\n",
    "Langtext": ""
  },
  "_15100027": {
    "posID": "159471",
    "scanID": "22597",
    "anr": "15100027",
    "TVanr": "",
    "code": "G-11-03-2A",
    "ean": "4712511825411",
    "marke": "fox",
    "bez2": "jersey L",
    "menge": "1",
    "ve": "St\u00fcck",
    "Dimensionstext": "blue\r\n",
    "Langtext": ""
  }
}

Answer 1

您可以使用Object.values()和Array.reduce()，如下所示:

var obj = {
  "_15800175": {
    "posID": "159469",
    "scanID": "22597",
    "anr": "15800175",
    "TVanr": "",
    "code": "G-09-27-2E",
    "ean": "4710069680575",
    "marke": "fox",
    "bez": "jersey yellow",
    "bez2": "size xl",
    "menge": "1",
    "ve": "St\u00fcck",
    "Dimensionstext": "TT9857BG\r\n",
    "Langtext": ""
  },
  "_15100027": {
    "posID": "159471",
    "scanID": "22597",
    "anr": "15100027",
    "TVanr": "",
    "code": "G-11-03-2A",
    "ean": "4712511825411",
    "marke": "fox",
    "bez2": "jersey L",
    "menge": "1",
    "ve": "St\u00fcck",
    "Dimensionstext": "blue\r\n",
    "Langtext": ""
  },
  "dummy": {
    "menge": "not-convertable-to-integer"
  },
   "dummy2": {
    // This item does NOT have "menge" property
  }
}

var sumMenge = Object.values(obj).reduce((sum, item) => sum + (!isNaN(+item.menge) || 0),0);
//                                                                    ^^^ This is to convert item.menge to number

console.log(sumMenge);

希望这有帮助