树的递归

Question

{"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。

Answer 1

var obj = {
"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": 999,
"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 getById(g,n) {
if (g.id==n) {
return g.name;
} else {
for (var i = 0; i < g.children.length; i++) {
var r = getById(g.children[i],n);
if (r)
return r;
}
return null;
}
}
alert(getById(obj,999));