使用javascript从阵列计算季度销售额和平均值

需要以对象格式计算季度销售额和平均值

var saleItem=[{“月”：“一月”，“日期”：“1”，“交易ID”：“1”，“salePrice”：“100”}，{“月”：“2”，“salePrice”：“200”}，{“月”：“3”，“日期”：“1”，“交易ID”：“3”，“salePrice”：“300”；“月”：“4”，“四月”，“日期”：“1”，“交易ID”：“4”，“salePrice”：“300”；“月”：“5月”，“日期”：“1”，“交易ID”：“4”，“salePrice:”300“，”月份“，”日期“：”1“，”交易ID:”4“，”salePrice:”300“，”月份“，”交易ID:”4“，”salePrice:”300“，”月份“，”日期“，”4“，”salePrice:”300“，”月份“，”9月“，”日期“，”1“，”交易ID:”4“，”salePrice:”300“，”月份“，”10月“，”日期“，”1“，”交易ID:”4“，”salePrice:“300”}，{“月份”：“11月”，“日期”：“1”，“交易ID”：“4”，“salePrice”：“300”}，{“月份”：“12月”，“日期”：“1”，“交易ID”：“4”，“salePrice”：“300”}]
功能getSumQuarterly（销售项目）{
//应该输出
/*
{季度：1，总价：xx，成交金额：1}，
{季度：2，总价：xx，成交金额：1}，
{季度：3，总价：xx，成交金额：1}，
{季度：4，总价：xx，成交金额：1}，
*/
}
函数getAverageQuarterly（销售项目）{
}

这是请求的代码

var saleItem =  [{"month":"January","date":"1","transactionId":"1","salePrice":"100"},{"month":"February","date":"1","transactionId":"2","salePrice":"200"},{"month":"March","date":"1","transactionId":"3","salePrice":"300"},{"month":"April","date":"1","transactionId":"4","salePrice":"300"},{"month":"May","date":"1","transactionId":"4","salePrice":"300"},{"month":"June","date":"1","transactionId":"4","salePrice":"300"},{"month":"July","date":"1","transactionId":"4","salePrice":"300"},{"month":"August","date":"1","transactionId":"4","salePrice":"300"},{"month":"September","date":"1","transactionId":"4","salePrice":"300"},{"month":"October","date":"1","transactionId":"4","salePrice":"300"},{"month":"November","date":"1","transactionId":"4","salePrice":"300"},{"month":"December","date":"1","transactionId":"4","salePrice":"300"}]

    function getSumQuarterly (saleItems) {
        var sum = [{
            totalPrices: 0,
            quarter: 1,
            transactionNums: 1
        }];
        var thisQuarterIndex = 0;
        saleItems.forEach(function (item, index) {
            var quarterIndex = Math.floor(index/3);
            if (quarterIndex === thisQuarterIndex) {
                sum[quarterIndex]['totalPrices'] = sum[quarterIndex]['totalPrices'] + parseInt(item.salePrice, 10);
            } else {
                thisQuarterIndex = quarterIndex;
                sum.push({});
                sum[quarterIndex]['totalPrices'] = parseInt(item.salePrice, 10);
                sum[quarterIndex]['quarter'] = quarterIndex + 1;
                sum[quarterIndex]['transactionNums'] = 1;
            }
        });
        return sum;
    }
    function getAverageQuarterly(saleItems) {
        var sum = getSumQuarterly(saleItems);
        var avg = [];
        sum.forEach(function (quarter) {
            avg.push(quarter.totalPrices/3);
        });
        return avg;
    }

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请提供您迄今为止尝试过的代码。此外，我在

saleItem

对象中没有看到任何月份的多笔交易，如果只有一笔交易，那么为什么您需要结果中的

transactionNums

？