js实现GROUP BY分类汇总并汇总数值

原始数据如：

arrTemp = [{
"operator": "2",
"testNumber": 22
},
{
"operator": "3",
"testNumber": 33
},
{
"operator": "1",
"testNumber": 11
},
{
"operator": "4",
"testNumber": 44
},
{
"operator": "2",
"testNumber": 22
},
{
"operator": "4",
"testNumber": 44
},
{
"operator": "1",
"testNumber": 11
}, {
"operator": "3",
"testNumber": 33
}
]

创建一个工具函数

 groupBy(arrTemp) {
 let keyContainerTemp = {} // 以key进行分组的临时对象
          arrTemp.forEach((item) => {
            keyContainerTemp[item.operatorKey] = keyContainerTemp[item.operatorKey] || []
            keyContainerTemp[item.operatorKey].push(item)
          })
          console.log(keyContainerTemp)
          let keysTemp = Object.keys(keyContainerTemp)
          keysTemp.forEach((keysItem) => {
            let count = 0
            keyContainerTemp[keysItem].forEach((item) => {
              count += item.testNumber // 遍历每种Key对应的数量汇总
            })
            this.arrGroupByResult.push({ operatorKey: keysItem, total: count })
          })
          console.log(this.arrGroupByResult)
          }

执行后，会将数组对象中，以operator为键值重复的会合并，testNumber 的值会累加。

[{
"operator": "1",
"testNumber": 22
},
{
"operator": "2",
"testNumber": 44
},
{
"operator": "3",
"testNumber": 66
},
{
"operator": "4",
"testNumber": 88
}]