// list数组转tree数组
function list2Tree(list, keyName, keyPname, keyValue = '') {
  let children = list.filter(item => item[keyPname] == keyValue);
  return children.map(item => {
    item.children = list2Tree(list, keyName, keyPname, item[keyName]);
    return item;
  })
}

// tree数组转list数组
function tree2list(tree) {
  const list = []
  const queue = [...tree]
  while (queue.length) {
    const node = queue.shift()
    const children = node.children
    if (children) {
      queue.push(...children)
    }
    list.push(node)
  }
  return list
}

// 随机字串
function randomString(len) {
  len = len || 8;
  let $chars = 'ABCDEFGHJKMNPQRSTWXYZabcdefhijkmnprstwxyz2345678';    /****默认去掉了容易混淆的字符oOLl,9gq,Vv,Uu,I1****/
  let maxPos = $chars.length;
  let str = '';
  for (let i = 0; i < len; i++) {
    str += $chars.charAt(Math.floor(Math.random() * maxPos));
  }
  return str;
}

// queryString转化成对象
function param2Obj(url) {
  const search = decodeURIComponent(url.split('?')[1]).replace(/\+/g, ' ')
  if (!search) {
    return {}
  }
  const obj = {}
  const searchArr = search.split('&')
  searchArr.forEach(v => {
    const index = v.indexOf('=')
    if (index !== -1) {
      const name = v.substring(0, index)
      const val = v.substring(index + 1, v.length)
      obj[name] = val
    }
  })
  return obj
}