SOURCE

let res = [
    {
        "PLATFORM": "",
        "MENUURL": "http://10.172.17.190:50001/root/sensitiveWord",
        "MENUTITLE": "敏感词库1",
        "MODULEID": "MGCK01",
        "OPENMETHOD": "",
        "PID": 1276,
        "ID": 1304,
        "USERROLEFUNMENU": []
    },
    {
        "PLATFORM": "",
        "MENUURL": "http://10.172.17.190:50001/root/homepage",
        "MENUTITLE": "首页展示",
        "MODULEID": "YJSY",
        "OPENMETHOD": "",
        "PID": 0,
        "ID": 1271,
        "USERROLEFUNMENU": []
    },
    {
        "PLATFORM": "",
        "MENUURL": "http://10.172.17.190:50001/root/alarmConfig",
        "MENUTITLE": "预警配置",
        "MODULEID": "YJPZ01",
        "OPENMETHOD": "",
        "PID": 1274,
        "ID": 1275,
        "USERROLEFUNMENU": []
    },
    {
        "PLATFORM": "",
        "MENUURL": "http://10.172.17.190:50001/root/alarmMake/#/History",
        "MENUTITLE": "敏感词库2",
        "MODULEID": "MGCK02",
        "OPENMETHOD": "",
        "PID": 1276,
        "ID": 1305,
        "USERROLEFUNMENU": []
    },
    {
        "PLATFORM": "全平台",
        "MENUURL": "http://10.172.17.190:50001/root/alarmMake/#/Make",
        "MENUTITLE": "预警制作",
        "MODULEID": "YJZZ001",
        "OPENMETHOD": "",
        "PID": 0,
        "ID": 68,
        "USERROLEFUNMENU": []
    },
    {
        "PLATFORM": "",
        "MENUURL": "http://10.172.17.190:50001/root/sensitiveWord/#/",
        "MENUTITLE": "敏感词库",
        "MODULEID": "MGCK",
        "OPENMETHOD": "",
        "PID": 1274,
        "ID": 1276,
        "USERROLEFUNMENU": []
    },
    {
        "PLATFORM": "",
        "MENUURL": "http://10.172.17.190:50001/root/alarmMake/#/Notice",
        "MENUTITLE": "通知制作",
        "MODULEID": "TZZZ",
        "OPENMETHOD": "",
        "PID": 0,
        "ID": 1273,
        "USERROLEFUNMENU": []
    },
    {
        "PLATFORM": "",
        "MENUURL": "http://10.172.17.190:50001/root/autoPublish/",
        "MENUTITLE": "自动发布渠道",
        "MODULEID": "ZDFBQD",
        "OPENMETHOD": "",
        "PID": 1274,
        "ID": 1277,
        "USERROLEFUNMENU": []
    },
    {
        "PLATFORM": "",
        "MENUURL": "http://10.172.17.190:50001/root/alarmConfig",
        "MENUTITLE": "预警配置",
        "MODULEID": "YJPZ",
        "OPENMETHOD": "",
        "PID": 0,
        "ID": 1274,
        "USERROLEFUNMENU": []
    },
    {
        "PLATFORM": "",
        "MENUURL": "http://10.172.17.190:50001/root/alarmMake/#/History",
        "MENUTITLE": "NIFS错误库",
        "MODULEID": "NIFS",
        "OPENMETHOD": "",
        "PID": 1274,
        "ID": 1278,
        "USERROLEFUNMENU": []
    }
]

function toTree(nodes) {
    let result = []
    //如果值是 Array，则为true; 否则为false。
    if (!Array.isArray(nodes)) {
        return result
    }
    //深拷贝，否则会影响原数组
    let node = JSON.parse(JSON.stringify(nodes))
    //根据父节点进行拼接子节点，
    node.forEach(item => delete item.children)//已经有的话就删掉
    //把每一项的引用放入map对象里
    let map = {}
    node.forEach(item => map[item.ID] = item)
    let newNode = []
    node.forEach(dt => {
        let parents = map[dt.PID]
        if (parents) {
            //如果 map[dt.pid] 有值 则 parents 为 dt 的父级
            //判断 parents 里有无child 如果没有则创建 如果有则直接把 dt push到child里
            ((parents.children) || (parents.children = [])).push(dt)
            //等同于：
            // if (!parents.child) {
            //     parents.child = []
            // }
            // (parents.child).push(dt)
        } else {
            newNode.push(dt)
        }
    })
    return newNode
}

console.log(toTree(res))