映射減少物件陣列的計數和總和

我有一個物件陣列，它具有布林值的屬性和一些整數值的屬性。例如

const arr = [{
    _id: "621bb15de2ecadf024da51d3",
    draw: false,
    pixel: false,
    tooltip: 1,
    points: 1,
    
  },
  {
    _id: "621bb15de2ecadf024da51d8",
    draw: false,
    pixel: true,
    tooltip: 0,
    points: 1,
    
  },
  {
    _id: "621bb15de2ecadf024da51da",
    draw: false,
    pixel: true,
    tooltip: 1,
    points: 1,
    
  },
  {
    _id: "621bb15de2ecadf024da51e5",
    draw: false,
    pixel: true,
    tooltip: 0,
    points: 1,
    
  },
  {
    _id: "621bb15de2ecadf024da51f8",
    draw: false,
    pixel: true,
    tooltip: 1,
    points: 1,
    
  },
  {
    _id: "621bb15ee2ecadf024da5222",
    draw: false,
    pixel: true,
    tooltip: 0,
    points: 1,
    
  },
  {
    _id: "621bb15ee2ecadf024da5230",
    draw: false,
    pixel: true,
    tooltip: 1,
    points: 1,
    
  },
  {
    _id: "621bb15fe2ecadf024da52f3",
    draw: false,
    pixel: false,
    tooltip: 1,
    points: 1,
    
  },
  {
    _id: "621bb160e2ecadf024da5375",
    draw: false,
    pixel: true,
    tooltip: 0,
    points: 1,
  }
]

我正在嘗試實作 and 的總和，tooltip以及它們為真的points計數draw和位置。pixel

const res = arr.reduce(function (
          acc,
          curr
        ) {
          return {
            tooltip: acc.tooltip   curr.tooltip,
            points:
              acc.points  
              curr.points,
          };
        });

我得到如下輸出，這對于總和是正確的，

{
  points: 9,
  tooltip: 5
}

但我也想要計算它的價值draw以及pixel它的價值在哪里。

Expected Result:
{
      points: 9,
      tooltip: 5,
      pixel: 7,
      draw: 0
    }

uj5u.com熱心網友回復：

只需使用與tooltipand相同的方式point，因為 在 2 個布林值之間使用運算子，這些布林值將被強制轉換為整數

const arr = [ { _id: '621bb15de2ecadf024da51d3', draw: false, pixel: false, tooltip: 1, points: 1, }, { _id: '621bb15de2ecadf024da51d8', draw: false, pixel: true, tooltip: 0, points: 1, }, { _id: '621bb15de2ecadf024da51da', draw: false, pixel: true, tooltip: 1, points: 1, }, { _id: '621bb15de2ecadf024da51e5', draw: false, pixel: true, tooltip: 0, points: 1, }, { _id: '621bb15de2ecadf024da51f8', draw: false, pixel: true, tooltip: 1, points: 1, }, { _id: '621bb15ee2ecadf024da5222', draw: false, pixel: true, tooltip: 0, points: 1, }, { _id: '621bb15ee2ecadf024da5230', draw: false, pixel: true, tooltip: 1, points: 1, }, { _id: '621bb15fe2ecadf024da52f3', draw: false, pixel: false, tooltip: 1, points: 1, }, { _id: '621bb160e2ecadf024da5375', draw: false, pixel: true, tooltip: 0, points: 1, }, ]

const res = arr.reduce(function (acc, curr) {
  return {
    tooltip: acc.tooltip   curr.tooltip,
    points: acc.points   curr.points,
    draw: acc.draw   curr.draw,
    pixel: acc.pixel   curr.pixel,
  }
})

console.log(res)

參考

12.8.3 加法運算子（ ）

uj5u.com熱心網友回復：

你可以試試這個：

let countPixel = 0;
let countDraw = 0;
const res = arr.reduce(function (
    acc,
    curr
  ) {
    if (curr.pixel == true) {
        countPixel  ;
    }  
    if (curr.draw == true) {
        countDraw  ;
    }
    return {
        tooltip: acc.tooltip   curr.tooltip,
        points: acc.points   curr.points,
        pixel: countPixel,
        draw: countDraw,
    };
});

標籤：javascript 数组 映射减少

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