function arr2obj(arr) { let obj = {}; obj['obj'] = {}; let temp = obj['obj']; for (let i = 0; i < arr.length; i++) { if (arr[i].parent == null) { temp.id = arr[i].id; temp.parent = arr[i].parent } else { temp.child = {}; temp = temp.child; temp.id = arr[i].id temp.parent = arr[i].parent } } return obj; }