js怎么实现递归生成tree结构数据

Question

原始数据形式为

var data = [
    { id: 1, name: "节点1", pid: 0 },
    { id: 2, name: "节点2", pid: 1 },
    { id: 3, name: "节点3", pid: 1 },
    { id: 4, name: "节点4", pid: 2 },
    { id: 5, name: "节点5", pid: 0 },
    { id: 6, name: "节点6", pid: 5 },
    { id: 7, name: "节点7", pid: 6 },
    { id: 8, name: "节点8", pid: 6 },
];

希望得到的结构是

var data = [
    {id: 1, name: "节点1", pid: 0 ,
        children:[
            { id: 2, name: "节点2", pid: 1,
                children:[
                    { id: 4, name: "节点4", pid: 2 },
                ],
            },
            { id: 3, name: "节点3", pid: 1},
        ]
    },
    {id: 5, name: "节点5", pid: 0 ,
        children:[
            { id: 6, name: "节点6", pid: 5,
                children:[
                    { id: 7, name: "节点7", pid: 6 },
                    { id: 8, name: "节点8", pid: 6 },
                ]
            },
        ]
    },
];

Answer 1

function getTree(ary, pid = 0) {
  return ary.filter(v => v.pid === pid).map(v => {
    const children = getTree(ary, v.id);
    if (children.length) v.children = getTree(ary, v.id);
    return v
  });
}

这样写会在原数组上添加children，不想修改原数组就在map里面做个浅拷贝