javascript - 数组需要根据键值对删除重复对象并返回总和 [fiddle]

Question

需要根据匹配的键删除重复的对象，但添加值。已经创建了片段和 fiddle 来查看。还在底部添加了预期结果。

我尝试了几种不同的方法，但无法获得预期的结果。我可以使用过滤器方法，但无法为匹配键添加值。请看一下 fiddle 或片段

fiddle link here

  let data2 = [{
        area: {
          type: "double",
          value: 50
        },
        areaName: {
          type: "string",
          value: "westside"
        },
        areaTitle: {
          type: "string",
          value: "rock"
        }
      },
      {
        area: {
          type: "double",
          value: 250
        },
        areaName: {
          type: "string",
          value: "north"
        },
        areaTitle: {
          type: "string",
          value: "sand"
        }
      },
      {
        area: {
          type: "double",
          value: 400
        },
        areaName: {
          type: "string",
          value: "westside"
        },
        areaTitle: {
          type: "string",
          value: "rock"
        }
      }
    ];

    var filterData2 =    Object.keys(data2).reduce((acc, elem) => {
      let getKeys = data2[elem];
      console.log(getKeys);

      return acc;
    }, []);

    console.log(filterData2);



    // Expected result  
    let result = [{
        Area: {
          type: "double",
          value: 450
        },
        AreaName: {
          type: "string",
          value: "westside"
        },
        AreaTitle: {
          type: "string",
          value: "rock"
        }
      },
      {
        Area: {
          type: "double",
          value: 250
        },
        AreaName: {
          type: "string",
          value: "north"
        },
        AreaTitle: {
          type: "string",
          value: "sand"
        }
      }
    ]

    console.log(result);

Answer 1

使用 reduce & Object.assign()如下所示，您可以获得所需的结果。在代码中添加解释作为注释。

注意 我将 Object.assign 用作 curr = Object.assign({}, x); 而不是 curr = x; 因为 curr = x; 稍后当我们更新 value 并找到现有对象时，它也会更新 value 的 数据2。使用 Object.assign({}, x); 这不会发生。

let data2 = [{
    area: {
      type: "double",
      value: 50
    },
    areaName: {
      type: "string",
      value: "westside"
    },
    areaTitle: {
      type: "string",
      value: "rock"
    }
  },
  {
    area: {
      type: "double",
      value: 250
    },
    areaName: {
      type: "string",
      value: "north"
    },
    areaTitle: {
      type: "string",
      value: "sand"
    }
  },
  {
    area: {
      type: "double",
      value: 400
    },
    areaName: {
      type: "string",
      value: "westside"
    },
    areaTitle: {
      type: "string",
      value: "rock"
    }
  }
];

// use reduce to iterate over array and produce result
var result = data2.reduce((a, x) => {
// find matching object from a.
  let curr = a.filter(y => y.areaName.value == x.areaName.value && y.areaTitle.value == x.areaTitle.value)[0];
  // if not exists then create new object and add into a
  // else add value to curr.area.value
  if (!curr) {
    curr = Object.assign({}, x);
    a.push(curr);
  } else {
    curr.area.value += x.area.value;
  }
  // return a
  return a;
}, []);

console.log(result);