javascript - 递归地遍历一个对象以找到 child ，沿途接 parent ，祖 parent 等

Question

我有一个包含菜单的对象。

我想输入一个类别ID并获取类别名称，然后向后移动找到它的parents。这在一个对象中并不容易，所以我正在考虑沿途捕获 parents。

我遇到的问题是如何在未找到最终子节点且无处可去时重置 父节点。

这就是我正在尝试的:

var data = [
	{
        "tree_id": "10",
        "name": "babies & children",
        "parent": null,
        "position": "1"
    }, {
        "tree_id": "2",
        "name": "clothing",
        "parent": null,
        "position": "1",
        "children": [{
            "tree_id": "15",
            "name": "kids",
            "parent": "2",
            "position": "3",
            "children": [{
                "tree_id": "78",
                "name": "fourToTen",
                "parent": "15",
                "position": "3",
                "children": [{
                    "tree_id": "102",
                    "name": "fourToSix",
                    "parent": "78",
                    "position": "3"
                }]
            }]
        }]
    }, {
        "tree_id": "55",
        "name": "toys",
        "parent": null,
        "position": "1",
        "children": [{
            "tree_id": "35",
            "name": "lego",
            "parent": "55",
            "position": "3"
        }]
    }
];

var crumbs = [];
function getParts(data, elem) {
    for(var i = 0; i < data.length; i++) {
        var obj = data[i];
        if(obj.children !== undefined){
            /* push parent into crumbs */
            crumbs.push(obj.name);
        	if(obj.children[0].tree_id === elem){
            	/* if we've found what we're looking, we're done */
                crumbs.push(obj.children[0].name);
                console.log(crumbs);
            } else {
            	/* reset parents */
                crumbs = []; /* <-- this is wrong here */
                /* not found, keep recursing */
            	getParts(obj.children, elem);
            }
        }
    }
}
/* I want this to return
 [
  "clothing",
  "kids",
  "fourToTen",
  "fourToSix"
 ]

 but it returns
 [
  "fourToTen",
  "fourToSix"
 ]
*/
getParts(data, '102');

问题是，我如何保存 parents 数组，直到我到达行尾并且找不到 child ，然后再重置它？

Here's a fiddle if that's your preferred playround

Answer 1

假设 category id = tree_id 和 category_name = name

您需要像对待树一样对待您的data 对象，然后横切它并沿途跟踪父对象。如果找到某些内容，则转储您需要的信息。

所以 data 基本上是您将要遍历的一组对象。

示例:

"use strict";
var data = [
    {
        "tree_id": "10",
        "name": "babies & children",
        "parent": null,
        "position": "1"
    },
    {
        "tree_id": "2",
        "name": "clothing",
        "parent": null,
        "position": "1",
        "children": [{
            "tree_id": "15",
            "name": "kids",
            "parent": "2",
            "position": "3",
            "children": [{
                "tree_id": "78",
                "name": "fourToTen",
                "parent": "15",
                "position": "3",
                "children": [{
                    "tree_id": "102",
                    "name": "fourToSix",
                    "parent": "78",
                    "position": "3"
                }]
            }]
        }]
    },
    {
        "tree_id": "55",
        "name": "toys",
        "parent": null,
        "position": "1",
        "children": [{
            "tree_id": "35",
            "name": "lego",
            "parent": "55",
            "position": "3"
        }]
    }
];

// Solution 
function transverse(root, tree, targetId) {
    tree.push({
        catId : root.tree_id,
        catName : root.name
    });

    /* this if() must come first otherwise fails if you want to stop before end */
    if (root.tree_id === targetId) {
        console.log("Found id:" + targetId+ ", name=" + root.name);
        console.log("Dumping parent info => " + JSON.stringify(tree));
        return tree;
    }

    if (root.hasOwnProperty("children") && root.children instanceof Array)
        root.children.forEach(child => {
            transverse(child, tree, targetId);
        });

}

data.forEach(item => {
     transverse(item, [], /*Looking for Id=*/"102");
});

console.log("done");

输出:

Found id:102, name=fourToSix
Dumping parent info => 
[
  {"catId":"2","catName":"clothing"},
  {"catId":"15","catName":"kids"},
  {"catId":"78","catName":"fourToTen"},
  {"catId":"102","catName":"fourToSix"}]
]