js_树形结构转嵌套结构

    var first = d.filter(e=> !!!e.pId);
    var last = d.filter(e=> !!!e.id);
    
    
        var map = {};
        var idMap = {};
    
        d.forEach(d => {
            idMap[d.id] = d;
            if(map[d.pId]) {
                map[d.pId].push(d);
            }else{
                map[d.pId] = [d];
            }
        });
    console.log(JSON.parse(JSON.stringify(map)));
        for(var key in map) {
            if(idMap[key]) {
    //             console.log("get children", key)
                idMap[key]['children'] = map[key];
                delete map[key];
            }
        }
    console.log(map);