先来个函数注释 :
/**
* 将有父子关系的一维数组转换成树形结构(多维)数据
* console.log(JSON.stringify(setTreeData(data), null, 2));
* ============================================
* @param {*Array} data 需要遍历的一维数组
*/
再来具体的代码 :
function fnSetTreeData(data) {
var data = [...data];
var tree = data.filter((father) => {
var branchArr = data.filter((child) => {
if (father.id == child.parentId) child._hasParent = true;
return father.id == child.parentId;
// MARK 为什么这样写就报错 ?
// if (father.id == child.parentId) child._hasParent = true;
// return child._hasParent
});
if (branchArr.length > 0) father.children = branchArr;
return !father._hasParent;
});
// MARK 为什么在这里还得加一个过滤
tree = tree.filter((item) => {
return !item._hasParent;
})
return tree
}
console.log(JSON.stringify(fnSetTreeData(data), null, 2));
至于怎么解决 循环引用 的问题, 先用 sort 给数组排序后, 再在每次filter 中 计数++如何 ?
得给一个测试数据 :
var data = [
{ id: 40, parentId: 31, note: "的萨达是" },
{ id: 20, parentId: 11, note: "的萨达是" },
{ id: 22, parentId: 20, note: "dsadas" },
{ id: 12, parentId: null, note: "dsadasad萨达s" },
{ id: 11, parentId: undefined, note: "dqwds" },
{ id: 24, parentId: 22, note: "搜索" },
{ id: 34, parentId: 22, note: "搜索" }
];
