如何使用for \ for每个循环从对象数组中高效搜索和获取项目？

Question

我有3个数组，分别称为A，B和C。A和B是字符串数组，C是对象数组。

A = ['Geography1', 'Geography2', 'Geography3', ...];//length will range from 100 to 500.
B = ['Jan 2018', 'Feb 2018', 'Mar 2018' ...];//length will range from 12 to 36.
C = [
   {"geoName": "Geography1", "month": "Jan 2018", "sales": 1, "growth": 12.11, "marketShare": 13.11},
{"geoName": "Geography1", "month": "Feb 2018", "sales": 2, "growth": 22.22, "marketShare": 23.22},
....
....
....
{"geoName": "Geography2", "month": "Jan 2018", "sales": 3, "growth": 33.33, "marketShare": 12.4},
{"geoName": "Geography2", "month": "Feb 2018", "sales": 4, "growth": 23.45, "marketShare": 12.4},
....
....
....
....
]; length will be A.length * B.length, approximately it will range from 1,200 to 18,000.

使用这些数组，并基于“销售”或“增长”，我需要生成另一个数组，例如D，它必须具有以下格式（显示的值是“销售”的值，如果我们按增长，增长过滤）值需要在每个地理位置\每月再次显示），使用for或for每个循环：

D = [
{"geoName":"Geography1", "Jan 2018": 1, "Feb 2018":2,....},
{"geoName":"Geography2", "Jan 2018": 3, "Feb 2018":4,....},
....
...

....
];

当前，这就是我的代码的样子，但是对于大型数据集而言，效率不高。执行需要很长时间：

function formatData(){
    D = [];
    var displayBy = "sales"; //or "growth"
    for each(geoDesc in A)
            {
                var row = {};
                row['geoName']= geoDesc;

                var val:Number;


                for each(var month:String in B)
                {

                    val = getValue(C, month, geoDesc, displayBy)
                    row[month] = val;

                }

                D.push(row);
            }
//D here will have final output
}

function getValue(source:Array, month:String, geoDesc:String,displayBy:String):Number
            {
                var value:Number = 0;
                var len:int = source.length;
                for(var i:int = 0; i < len; i++)
                {
                    var item:Object = source[i];
                    if(item['month'] == month && item['geoName'] == geoDesc)
                    {
                        value = item[displayBy];
                        break;
                    }
                }

                return value; 
}