基于ES6语法的父子对象列表转树形的方法

···
const list = [
{ id: 1, name: 1, pid: 0 },
{ id: 2, name: 12, pid: 1 },
{ id: 3, name: 13, pid: 2 },
{ id: 4, name: 14, pid: 3 },
{ id: 5, name: 15, pid: 4 },
{ id: 6, name: 16, pid: 1 },
{ id: 7, name: 18, pid: 6 },
{ id: 8, name: 19, pid: 7 }
]

/**

• @param {any[]} list
  */
  function listToTree(list) {
  // hash
  const map = {}
  for (const item of list) {
  map[item.id] = item
  }
  for (const item of list) {
  if (!(item.pid > 0)) {
  continue
  }
  const parent = map[item.pid]
  if (typeof parent.children === 'undefined') {
  parent.children = []
  }
  parent.children.push(item)
  }
  return list.filter(i => i.pid === 0)
  }
  ···