扁平化递归查询树中某一个节点及当前节点及以下的所有节点

var arr = [{name: 1, children: [{name: 2, children: [{name: 3, children: []}]}]}]
let arrs = dgtest(arr[0])

function dgtest(root) {
let arr = []
if (root.children.length) {
　　arr = root.children.flatMap(child=>{dgtest(child)})

}
return [root, ...arr]

}

 

d第二种 去掉了children

let tree = [
    {
        "id": 1,
        "name": "1",
        "pid": 0,
        "children": [
            {
                "id": 2,
                "name": "2",
                "pid": 1,
                "children": []
            },
            {
                "id": 3,
                "name": "3",
                "pid": 1,
                "children": [
                   {
                     "id": 4,
                     "name": "4",
                     "pid": 3,
                     "children": []
                   }
                ]
            }
        ]
    }
]
function treeToArray(tree) {
  let res = []
  for (const item of tree) {
    const { children, ...i } = item
    if (children && children.length) {
      res = res.concat(treeToArray(children))
    }
    res.push(i)
  }
  return res
}
treeToArray(tree)