WangNingning1994

<template>
  <el-table
    :data="tableData"
    style="width: 100%"
    :span-method="arraySpanMethod"
    >
    <el-table-column
      prop="one"
      label="一级分类"
      width="180">

WangNingning1994

  const numArr = [ [1,2,3], [4,5,6] ];
  const initialValue = 0;
  const totalNum = numArr.reduce(
    (acc, curr) => acc + curr.reduce((acc_, curr_) => acc_ + curr_, 0),
    initialValue
  );

WangNingning1994

// 对象数组分类方法
const groupBy = (items, key) => items.reduce(
  (result, item) => ({
    ...result,
    [item[key]]: [
      ...(result[item[key]] || []),
      item,
    ],
  }), 
  {},

WangNingning1994

const groupBy = (items, key) => {
  let map = new Map();
  items.forEach(item => {
    let val = item[key];
    if (map.get(val)) {
      map.get(val).push(item)
    } else {
      map.set(val, []);
      map.get(val).push(item)
    }