递归中，调用forEach方法问题

Posted 2020-10-19 兔子只吃胡萝卜

 1     function traverse(objNmae,obj,url){
 2         url = url || objNmae;
 3         if(typeof obj === "object" ){
 4             //for in 方法
 5             for(let i in obj){
 6                 url += ("=>"+i);
 7                 arguments.callee(i,obj[i],url);
 8             }
 9             //forEach 方法
10             obj.forEach(function(value,index){
11                 url += ("=>"+index);
12                 arguments.callee(index,value,url);
13             });
14         }else if(typeof obj === "string" || typeof obj === "number"){
15             console.log(url+objNmae+":"+obj);
16             return;
17         }
18     }

for in 方法 和forEach方法，方法的功能是同样的，就是遍历一个对象集，并且输出对象中所有末端元素的路径。

接下来我们对下面的这个对象进行遍历

     var itg_data        = [{"itg_num":"1200","itg_category":"rew_gold","itg_reward_num":"1","itg_sum_num":"661","itg_place":"","pic":"\\/Uploads\\/game\\/reward\\/357203060783037259.png","goods_unit":"\\u679a","goods_name":null},{"itg_num":"1400","itg_category":"rew_goods","itg_reward_num":"4","itg_sum_num":"656","itg_place":"fresh","pic":"\\/Uploads\\/UploadsShop\\/2017-07-05\\/595c823c86cf7.jpg","goods_unit":"\\u679a","goods_name":"\\u65e0\\u6297\\u571f\\u9e21\\u86cb"},{"itg_num":"1600","itg_category":"rew_gold","itg_reward_num":"2","itg_sum_num":"555","itg_place":"","pic":"\\/Uploads\\/game\\/reward\\/357203060783037259.png","goods_unit":"\\u679a","goods_name":null},{"itg_num":"1800","itg_category":"rew_goods","itg_reward_num":"8","itg_sum_num":"492","itg_place":"fresh","pic":"\\/Uploads\\/UploadsShop\\/2017-07-05\\/595c823c86cf7.jpg","goods_unit":"\\u679a","goods_name":"\\u65e0\\u6297\\u571f\\u9e21\\u86cb"},{"itg_num":"2500","itg_category":"rew_goods","itg_reward_num":"1","itg_sum_num":"555","itg_place":"fresh","pic":"\\/Uploads\\/UploadsShop\\/2017-06-22\\/594b602919d9d.jpg","goods_unit":"\\u53ea","goods_name":"\\u6bcd\\u9e21\\uff08\\u6563\\u517b\\uff09"}];

for in 方法

 

但是在这里 forEach方法会报错，

 

提示最大调用栈大小超过。但是使用for in 就没有这样的问题

由此可见，forEach在递归中因为，有些对象树过深，对导致其堆栈溢出，forEach不适合用在递归中，可以使用for in