問題描述

現(xiàn)在有以下數(shù)據(jù)結構:

[{ id: 1, pid: 0, name: '年級'}, { id: 2, pid: 1, name: '一年級'}, { id: 3, pid: 1, name: '二年級'}, { id: 4, pid: 0, name: '專業(yè)'}, { id: 5, pid: 4, name: '單片機開發(fā)'}]

寫一個JS方法，將其轉換成以下格式數(shù)據(jù)：

[{ id: 1, pid: 0, name: '年級', children: [{id: 2,pid: 1,name: '一年級' }, {id: 3,pid: 1,name: '二年級' }]}, { id: 4, pid: 0, name: '專業(yè)', children: [{id: 5,pid: 4,name: '單片機開發(fā)' }]}]

問題解答

var list = [{ id: 1, pid: 0, name: '年級'}, { id: 2, pid: 1, name: '一年級'}, { id: 3, pid: 1, name: '二年級'}, { id: 4, pid: 0, name: '專業(yè)'}, { id: 5, pid: 4, name: '單片機開發(fā)'}];function parseList (list) { var map = {}; list.forEach(function (item) {if (!map[item.id]) { map[item.id] = item; } }); list.forEach(function (item) {if (item.pid != 0) { map[item.pid].chidren ? map[item.pid].chidren.push(item) : map[item.pid].chidren = [item];} }); return list.filter(function (item) {return item.pid === 0; });}var newList = parseList(list);回答2：

var list = [ { id: 1, pid: 0, name: '年級' }, { id: 2, pid: 1, name: '一年級' }, { id: 3, pid: 1, name: '二年級' }, { id: 4, pid: 0, name: '專業(yè)' }, { id: 5, pid: 4, name: '單片機開發(fā)' }];// 生成查找表，可以按 id 查到節(jié)點const dict = list.reduce((all, item) => { all[item.id] = item; return all;}, {});// 由于原始數(shù)據(jù)沒有 id 為 0 的根節(jié)點，// 這里模擬一個，最終它的 children 就是實際的所有根節(jié)點var root = { id: 0};dict[0] = root;// 循環(huán)添加關系list.forEach(item => { const parent = dict[item.pid]; // 確保父節(jié)點的 children 存在 parent.children = parent.children || []; parent.children.push(item);});// 輸出結果 root.children// 注意，root 不是結果，root.children 才是console.log(JSON.stringify(root.children, null, 4));

參考一下

var sortedData = data.reduce((result, item) => { result[item.id] = Object.assign({}, item) return result}, [])var result = sortedData.reduce((result, item) => { if (item.pid === 0) { result.push(item) } else { if (sortedData[item.pid].children) { sortedData[item.pid].children.push(item) } else { sortedData[item.pid].children = [item] } } return result}, [])