json转树状结构（js）

转自： http://rockyuse.iteye.com/blog/1541308

/** 
 * json格式转树状结构 
 * @param   {json}      json数据 
 * @param   {String}    id的字符串 
 * @param   {String}    父id的字符串 
 * @param   {String}    children的字符串 
 * @return  {Array}     数组 
 */  
function transData(a, idStr, pidStr, chindrenStr){  
    var r = [], hash = {}, id = idStr, pid = pidStr, children = chindrenStr, i = 0, j = 0, len = a.length;  
    for(; i < len; i++){  
        hash[a[i][id]] = a[i];  
    }  
    for(; j < len; j++){  
        var aVal = a[j], hashVP = hash[aVal[pid]];  
        if(hashVP){  
            !hashVP[children] && (hashVP[children] = []);  
            hashVP[children].push(aVal);  
        }else{  
            r.push(aVal);  
        }  
    }  
    return r;  
}  
  
var jsonData = eval('[
	{"id":"4","pid":"1","name":"大家电"},
	{"id":"5","pid":"1","name":"生活电器"},
	{"id":"1","pid":"0","name":"家用电器"},
	{"id":"2","pid":"0","name":"服饰"},
	{"id":"3","pid":"0","name":"化妆"},
	{"id":"7","pid":"4","name":"空调"},
	{"id":"8","pid":"4","name":"冰箱"},
	{"id":"9","pid":"4","name":"洗衣机"},
	{"id":"10","pid":"4","name":"热水器"},
	{"id":"11","pid":"3","name":"面部护理"},
	{"id":"12","pid":"3","name":"口腔护理"},
	{"id":"13","pid":"2","name":"男装"},
	{"id":"14","pid":"2","name":"女装"},
	{"id":"15","pid":"7","name":"海尔空调"},
	{"id":"16","pid":"7","name":"美的空调"},
	{"id":"19","pid":"5","name":"加湿器"},
	{"id":"20","pid":"5","name":"电熨斗"}
	]');  
  
var jsonDataTree = transData(jsonData, 'id', 'pid', 'chindren');  
console.log(jsonDataTree);  
//结果如下：
[
	{"id":"1","pid":"0","name":"家用电器", "chindren":[
		{"id":"4","pid":"1","name":"大家电", "chindren":[
			{"id":"7","pid":"4","name":"空调", "chindren":[
				{"id":"15","pid":"7","name":"海尔空调"},
				{"id":"16","pid":"7","name":"美的空调"}
			]},
			{"id":"8","pid":"4","name":"冰箱"},
			{"id":"9","pid":"4","name":"洗衣机"},
			{"id":"10","pid":"4","name":"热水器"}
		]},
		{"id":"5","pid":"1","name":"生活电器","chindren":[
			{"id":"19","pid":"5","name":"加湿器"},
			{"id":"20","pid":"5","name":"电熨斗"}
		]}
	]},
	{"id":"2","pid":"0","name":"服饰","chindren":[
		{"id":"13","pid":"2","name":"男装"},
		{"id":"14","pid":"2","name":"女装"}
	]},
	{"id":"3","pid":"0","name":"化妆","chindren":[
		{"id":"11","pid":"3","name":"面部护理"},
		{"id":"12","pid":"3","name":"口腔护理"}
	]}
]