Object.keys（arr）.reduce（）返回undefined

Question

我正在从像这样的数组中创建一个对象

var val = $(this).val();
 var type = " " + $("#backing").val() + " ";
      var arr = $.extend({}, comb_arr[type]);

结果

var arr = {"1-4  ": "$10.10 ", "5-9  ": "$8.34 ", "10-24  ": "$7.71 ", "25-49  ": "$7.21 "}

当我通过输出运行以下代码时未定义

var price = Object.keys(arr).reduce((a, c) => {
     var s = c.trim();
     if(/\d+\-\d+/.test(s)){
        var range = s.split("-");
        if(val >= parseInt(range[0]) && val <= parseInt(range[1])){
            a = comb_arr[c];
        }
     }else{
        s = s.replace(/\D/g, "");
        if(val >= s){
            a = comb_arr[c];
        }
     }
     return a;
  },0);

欢迎所有想法！