数组转树形数据

const nodes = [{ id: 3, name: '节点C', pid: 1 },{ id: 6, name: '节点F', pid: 3 },{ id: 0, name: 'root', pid: null },{ id: 1, name: '节点A', pid: 0 },{ id: 8, name: '节点H', pid: 4 },{ id: 4, name: '节点D', pid: 1 },{ id: 2, name: '节点B', pid: 0 },{ id: 5, name: '节点E', pid: 2 },{ id: 7, name: '节点G', pid: 2 },{ id: 9, name: '节点I', pid: 5 }
];function convert(data) {if (!Array.isArray(data)) {new Error('data must be an array');return;}let result;let map = {};data.forEach(item => {//id作为keymap[item.id] = item;});data.forEach(item => {// item.pid 为0时 返回underfinedlet parent = map[item.pid];if (parent) {//如果用children，就直接push,没有就初始化数组(parent.children || (parent.children = [])).push(item);} else {// 这里push的item是pid为0的数据result = item;}});return result;
}console.log(convert(nodes));

{id: 0,name: 'root',pid: null,children: [{ id: 1, name: '节点A', pid: 0, children: [Array] },{ id: 2, name: '节点B', pid: 0, children: [Array] }]}