相关疑难解决方法(0)

说我想要a.x为每个元素求和arr.

arr = [{x:1},{x:2},{x:4}]
arr.reduce(function(a,b){return a.x + b.x})
>> NaN

我有理由相信ax在某些时候是不确定的.

以下工作正常

arr = [1,2,4]
arr.reduce(function(a,b){return a + b})
>> 7

我在第一个例子中做错了什么？

我有类似的代码如下:

var temp=[{"name":"Agency","y":32,"drilldown":{"name":"Agency","categories":["APPS & SI","ERS"],"data":[24,8]}},{"name":"ER","y":60,"drilldown":{"name":"ER","categories":["APPS & SI","ERS"],"data":[7,53]}},{"name":"Direct","y":60,"drilldown":{"name":"Direct","categories":["APPS & SI","ERS"],"data":[31,29]}}];

var reduced=temp.reduce(function (a,b) {
        return a.y + b.y;
    });
console.log(reduced) // returns NAN