按对象中的类型累加值

Question

我有一个包含对象的数组，每个对象都有不同的类型（墙类型）。我正在尝试累积每个区域的总值以检查每面墙的总面积：

const walls = [
  {
    typeName: "Sandwichelement - 480mm",
    area: 28.165,
  },
  {
    typeName: "Sandwichelement - 480mm",
    area: 22.165,
  },
  {
    typeName: "Beton vægelement - 150mm",
    area: 89.15,
  },
  {
    typeName: "Beton vægelement - 150mm",
    area: 165,
  },
  {
    typeName: "Fundament - 900mm",
    area: 45.2,
  },
  {
    typeName: "Fundament - 900mm",
    area: 16.5,
  },
];

const result = walls.reduce((acc, val) => {
  acc[val.typeName] = { totalArea: 0 };

  acc[val.typeName]["totalArea"] += val.area;

//the result:
//{
//"Beton vægelement - 150mm": {totalArea: 254.15},
//"Fundament - 900mm": {totalArea: 61.7},
//"Sandwichelement - 480mm": {totalArea: 50.33}
//}

  return acc;
}, {});

console.log(result);

Answer 1

遍历它并更新结果对象：

const result = {};

for (const {typeName, area} of walls) {
    if (!result[typeName]) {
        result[typeName] = {totalArea: 0};
    }

    result[typeName].totalArea += area;
}

console.log(result);
/*
{
"Beton vægelement - 150mm": {totalArea: 254.15},
"Fundament - 900mm": {totalArea: 61.7},
"Sandwichelement - 480mm": {totalArea: 50.33}
}
*/

const walls = [
  {
    typeName: "Sandwichelement - 480mm",
    area: 28.165,
  },
  {
    typeName: "Sandwichelement - 480mm",
    area: 22.165,
  },
  {
    typeName: "Beton vægelement - 150mm",
    area: 89.15,
  },
  {
    typeName: "Beton vægelement - 150mm",
    area: 165,
  },
  {
    typeName: "Fundament - 900mm",
    area: 45.2,
  },
  {
    typeName: "Fundament - 900mm",
    area: 16.5,
  },
];

const result = {};

for (const {typeName, area} of walls) {
    if (!result[typeName]) {
        result[typeName] = {totalArea: 0};
    }

    result[typeName].totalArea += area;
}

console.log(result);
/*
{
"Beton vægelement - 150mm": {totalArea: 254.15},
"Fundament - 900mm": {totalArea: 61.7},
"Sandwichelement - 480mm": {totalArea: 50.33}
}
*/

Answer 2

你只需要迭代你的墙数组。在我的例子中，我使用了一个 foreach 循环并将带有总计的对象添加到它。

const walls = [
  {
    typeName: "Sandwichelement - 480mm",
    area: 28.165,
  },
  {
    typeName: "Sandwichelement - 480mm",
    area: 22.165,
  },
  {
    typeName: "Beton vægelement - 150mm",
    area: 89.15,
  },
  {
    typeName: "Beton vægelement - 150mm",
    area: 165,
  },
  {
    typeName: "Fundament - 900mm",
    area: 45.2,
  },
  {
    typeName: "Fundament - 900mm",
    area: 16.5,
  },
];

const s = {};
walls.forEach((val) => {
  if (! s[val.typeName]){
    s[val.typeName] = { totalArea: 0 };
    s[val.typeName]["totalArea"] += val.area;     } else {
      s[val.typeName]["totalArea"] += val.area;
  }
    
});

console.log("sum", s)

按对象中的类型累加值

Accumulate value by types in objects

javascript