JavaScript中动态实现对象数组多属性累计求和方案

架构老林

2026-9-23

实现思路

首先提取数组首个元素中值为数值类型的键列表，自动跳过subject这类非数值字段，不需要手动指定
维护一个累计值存储对象，记录各数值键的当前滚动总和
遍历原数组的每个元素，基于原对象生成新对象，对每个数值键累加更新值，不修改原数组数据

实现代码

let a = [
  {"subject":  "Civil", "a": 100, "b":50, "c":100 },
  {"subject":  "aero",  "a": 200, "b":130,"c":100 },
  {"subject":  "tribe", "a": 100, "b":100,"c":600 },
  {"subject":  "solen", "a": 400, "b":150,"c":100},
  {"subject":  "space", "a": 100, "b":100,"c":900 }
];

// 提取所有数值类型的键
const numKeys = Object.keys(a[0]).filter(key => typeof a[0][key] === 'number');
// 初始化累计对象
const sumCache = Object.fromEntries(numKeys.map(key => [key, 0]));
// 遍历计算滚动累计
const result = a.map(item => {
  const newItem = {...item};
  numKeys.forEach(key => {
    sumCache[key] += item[key];
    newItem[key] = sumCache[key];
  });
  return newItem;
});

console.log(result);