SOURCE

const  groupBy = (array, f) => {
  const groups = {}
    array.forEach(function (o) {
    const group = JSON.stringify(f(o))
    groups[group] = groups[group] || []
    groups[group].push(o)
  })
  return Object.keys(groups).map(function (group) {
    return groups[group]
  })
}
 
const arrayGroupBy = (list, groupId) => {
  const sorted = groupBy(list, function (item) {
    return [item[groupId]]
  })
  return sorted
}
 
const gridData =[
  {
     id: '22',
     name: '张三',
     code: '15'
  },
  {
     id: '23',
     name: '李四',
     code: '15'
  },
  {
     id: '24',
     name: '李五',
     code: '14'
  }
]
const mergeList = arrayGroupBy(gridData, 'code')
console.log(mergeList)