树的递归

{"id": 1,
"pid": 0,
"code": "310000",
"name": "浙江省",
"type": 0,
"memo": "",
"info": {},
"children": [
{
"id": 177,
"pid": 1,
"code": "",
"name": "温州市",
"type": 0,
"memo": "",
"info": {},
"children": []
},
{
"id": 3,
"pid": 1,
"code": "310000",
"name": "杭州市",
"type": 0,
"memo": "",
"info": {},
"children": [{
"id": 179,
"pid": 3,
"code": "",
"name": "西湖区",
"type": 0,
"memo": "",
"info": {},
"children": [
{"id": 179,
"pid": 179,
"code": "",
"name": "文一路",
"type": 0,
"memo": "",
"info": {},
"children": []}
]
}]
},{
"id": 11,
"pid": 1,
"code": "",
"name": "宁波市",
"type": 0,
"memo": "",
"info": {},
"children": []
}
]
}
这是json格式的树结构，比如：我想要取得id为179下面的children，采用递归怎么写啊。用js写一下，java也行。

解决方案 »

  1.   

    <!DOCTYPE html>
    <html><head>
        <meta charset="utf-8">
        <title></title>
    </head><body>
        <script>
            var json = {
                "id": 1,
                "pid": 0,
                "code": "310000",
                "name": "浙江省",
                "type": 0,
                "memo": "",
                "info": {},
                "children": [{
                        "id": 177,
                        "pid": 1,
                        "code": "",
                        "name": "温州市",
                        "type": 0,
                        "memo": "",
                        "info": {},
                        "children": []
                    },
                    {
                        "id": 3,
                        "pid": 1,
                        "code": "310000",
                        "name": "杭州市",
                        "type": 0,
                        "memo": "",
                        "info": {},
                        "children": [{
                            "id": 179,
                            "pid": 3,
                            "code": "",
                            "name": "西湖区",
                            "type": 0,
                            "memo": "",
                            "info": {},
                            "children": [{
                                "id": 180,
                                "pid": 179,
                                "code": "",
                                "name": "文一路",
                                "type": 0,
                                "memo": "",
                                "info": {},
                                "children": []
                            }]
                        }]
                    }, {
                        "id": 11,
                        "pid": 1,
                        "code": "",
                        "name": "宁波市",
                        "type": 0,
                        "memo": "",
                        "info": {},
                        "children": []
                    }
                ]
            };        function treeWalk(node, targetId) {
                if (!node) {
                    return;
                }            // 找到结果，结束递归
                if (node.id == targetId) {
                    window.foundChildren = node.children;
                    return;
                }            // 按 children 顺序深度优先递归遍历树
                var children = node.children;
                children.forEach((n) => {
                    treeWalk(n, targetId);
                });
            }        treeWalk(json, 179);
            console.log(JSON.stringify(window.foundChildren));
        </script>
    </body></html>
      

  2.   

    "(n) =>   "这个写法没看懂
      

  3.   

      var children = node.children;
                children.forEach((n) => {
                    treeWalk(n, targetId);
     });   这个=>是啥意思？
      

  4.   

    lambda表达式
      

  5.   

    lambda表达式
    你自己改成循环children数组,将其中元素作为参数递归调用treeWalk方法即可