JavaScript合并数组对象中key相同的数据（将数组里某个属性相同的对象合并成一个数组）三种方案。

原始数据：

let resData = [
      {
        "name": "住院医疗最高报销",
        "tagName": "医疗",
        "insuredAmount": "6000"
      },
      {
        "name": "身故赔付",
        "tagName": "寿险",
        "insuredAmount": "36.00"
      },
      {
        "name": "烦死了免费陈述事实",
        "tagName": "寿险",
        "insuredAmount": "8888.00"
      },
      {
        "name": "你好，噜噜噜",
        "tagName": "寿险",
        "insuredAmount": "66.00"
      },
      {
        "name": "120种重大疾病确诊赔付",
        "tagName": "重疾",
        "insuredAmount": "350000"
      }
    ]

想得到的结果为：

let Data = [
      {
        "tagName": "医疗",
        dataInfo: [
          {
            "name": "住院医疗最高报销",
            "tagName": "医疗",
            "insuredAmount": "6000"
          }
        ]
      },
      {
        "tagName": "寿险",
        dataInfo: [
          {
            "name": "身故赔付",
            "tagName": "寿险",
            "insuredAmount": "36.00"
          },
          {
            "name": "烦死了免费陈述事实",
            "tagName": "寿险",
            "insuredAmount": "8888.00"
          },
          {
            "name": "你好，噜噜噜",
            "tagName": "寿险",
            "insuredAmount": "66.00"
          },
        ]
      },
      {
        "tagName": "重疾",
        dataInfo: [
          {
            "name": "120种重大疾病确诊赔付",
            "tagName": "重疾",
            "insuredAmount": "350000"
          }
        ]
      }
    ]

• 方法一：

let tempArr = [];
let Data = [];
for (let i = 0; i < resData.length; i++) {
   if (tempArr.indexOf(resData[i].tagName) === -1) {
     Data.push({
       tagName: resData[i].tagName,
       dataInfo: [resData[i]]
     });
     tempArr.push(resData[i].tagName);
   } else {
     for (let j = 0; j < Data.length; j++) {
       if (Data[j].tagName == resData[i].tagName) {
         Data[j].dataInfo.push(resData[i]);
         break;
       }
     }
   }
 }
 console.log(Data);

• 方法二：

let dataInfo = {};
resData.forEach((item, index) => {
	let { tagName } = item;
	if (!dataInfo[tagName]) {
		dataInfo[tagName] = {
			tagName,			
			child: []
		}
	}
	dataInfo[tagName].child.push(item);
});
let list = Object.values(dataInfo); // list 转换成功的数据
console.log(list)

• 方法三：

  let newArr = [];
  resData.forEach((item) => {
    const parent = newArr.find((c) => c.tagName === item.tagName);
    if (parent) {
      parent.dataInfo.push(item);
    } else {
      const obj = {
        tagName: item.tagName,
        dataInfo: [item],
      };
      newArr.push(obj);
    }
  });
  console.log(newArr);