我有一個物件陣列，每個物件都有欄位id，parentId和position。位置欄位存盤該專案的相對位置，所以如果我做一個這樣的排序函式：
object.sort((a, b) => {
if(a.position < b. position) return -1;
if(a.position > b. position) return 1;
return 0;
})
它最終是這樣的：
{id: 1, parentId: null, position: 0}
{id: 3, parentId: null, position: 1}
{id: 5, parentId: 1, position: 1}
{id: 6, parentId: 3, position: 1}
{id: 4, parentId: null, position: 2}
{id: 2, parentId: 1, position: 2}
如何檢查 parentId 和 position 以這樣結束？
{id: 1, parentId: null, position: 0}
{id: 5, parentId: 1, position: 1}
{id: 2, parentId: 1, position: 2}
{id: 3, parentId: null, position: 1}
{id: 6, parentId: 3, position: 1}
{id: 4, parentId: null, position: 2}
uj5u.com熱心網友回復：
您可以按它們收集所有節點，并從有序陣列parentId開始獲得有序結果。null
const
getNodes = parent => (parents[parent] || [])
.sort((a, b) => a.position - b.position)
.flatMap(o => [o, ...getNodes(o.id)]),
data = [{ id: 1, parentId: null, position: 0 }, { id: 2, parentId: 1, position: 2 }, { id: 3, parentId: null, position: 1 }, { id: 6, parentId: 3, position: 1 }, { id: 4, parentId: null, position: 2 }, { id: 5, parentId: 1, position: 1 }],
parents = data.reduce((r, o) => ((r[o.parentId] ??= []).push(o), r), {}),
result = getNodes(null);
console.log(result);
console.log(parents);.as-console-wrapper { max-height: 100% !important; top: 0; }轉載請註明出處，本文鏈接：https://www.uj5u.com/houduan/444759.html
標籤：javascript 排序
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