Js操作数据返回层级树

getTreeData2() {
    let parentArr = columnData.filter(l = > l.PARENTID === "");
    this.columnData = this.getTreeData(columnData, parentArr)
},
getTreeData(list, dataArr) {
    dataArr.map((pNode) = > {
        let childObj = [];
        list.map((cNode) = > {
            if (pNode.ID_ === cNode.PARENTID) {
                childObj.push(cNode)
            }
        });
        pNode.children = childObj;
        if (childObj.length > 0) {
            this.getTreeData(list, childObj)
        }
    });
    return dataArr
}