function treelistarrid=0 let arry = arrforEachitem= ifitemparent_id=0 let obj = iditemid titleitemtitle childrentreelistarritemid arrypushobj retur

function treelist(arr, id = 0) { let arry = []; arr.forEach(item => { if (item.parent_id === id) { let obj = { id: item.id, title: item.title, children: treelist(arr, item.id) }; arry.push(obj); } }); return arry; }

console.log(treelist(arrayData));