计算JavaScript对象中属性百分比的变化

Calculating change in percent of the properties in JavaScript objects

本文关键字：百分比 变化 属性 JavaScript 对象 计算      更新时间：2023-09-26

我想通过它的先前范围计算数据范围的百分比变化。

下面是我正在做的一个例子:

下面是一个对象数组，我需要根据WeekNo范围的选择来计算displayAd_imp, videoAd_imp和tv_impbased属性的百分比变化。

var objArr = [{
    "Title": "July 13 - July 19 2014",
        "displayAd_imp": "3,500",
        "videoAd_imp": "1.5",
        "tv_imp": "0.52",
        "Date": "2014-07-17T00:00:00.000Z",
        "WeekNo": 29
}, {
    "Title": "July 20 - July 26 2014",
        "displayAd_imp": "1,600",
        "videoAd_imp": "2.55",
        "tv_imp": "0.052",
        "Date": "2014-07-24T00:00:00.000Z",
        "WeekNo": 30
}, {
    "Title": "July 27 - Aug 2 2014",
        "displayAd_imp": "1,500",
        "videoAd_imp": "2.1",
        "tv_imp": "0.122",
        "Date": "2014-07-31T00:00:00.000Z",
        "WeekNo": 31
}, {
    "Title": "Aug 3 - Aug 9 2014",
        "displayAd_imp": "1,500",
        "videoAd_imp": "1.99",
        "tv_imp": "0.254",
        "Date": "2014-08-07T00:00:00.000Z",
        "WeekNo": 32
}, {
    "Title": "Aug 10 - Aug 17 2014",
        "displayAd_imp": "1,400",
        "videoAd_imp": "2.0",
        "tv_imp": ".235",
        "Date": "2014-08-14T00:00:00.000Z",
        "WeekNo": 33
}];

在下面的方法中，我试图通过首先过滤具有start和end WeekNo的数据来实现此任务，然后计算该数据的总和。这是一个jsfiddle的工作示例。

function CalcWeekRange(data,begin,end){
    //console.log(data,begin, end);
    var newArr = data.filter(function(item){
        return (item.WeekNo >= begin && item.WeekNo <= end);
    });
    var sumArr = [newArr.reduce(function (acc, x) {
        Object.keys(acc).forEach(function (k) {
        acc[k] += Number(x[k]);
                });
                return acc;
            }, {
                displayAd_imp: 0,
                videoAd_imp: 0,
                tv_imp: 0,
            })];
            console.log(sumArr);
}

我遇到困难的部分是通过获得前一个范围的总和，然后是当前/以前- 1来计算该时期的百分比变化。例如，在上面的示例中，我们调用CalcWeekRange(objArr,32,33);。

displayAd_imp的百分比变化逻辑将是:

当前周数(32,33):1400+1500 = 2900(我们在sumArr中有这部分)

前几周(30、31):1600+1500 = 3100

%改变:(2900/3100-1)* 100 = -6.45 (注:允许负)

上述情况也适用于其他属性。

希望问题和例子是清楚的，谢谢你的时间!

你的意思是像这样除了你上面的对象数组和代码?

var jCurrent = CalcWeekRange(objArr,32,33);
var jPrevious = CalcWeekRange(objArr,30,31);
var jCurrentDisplay = jCurrent[0].displayAd_imp;
var jPreviousDisplay = jPrevious[0].displayAd_imp;
var result = (jCurrentDisplay/jPreviousDisplay-1)*100;
console.log("result ", result);

调整你的jsFiddle: jsFiddle

更新:如果您想获得基于当前实际周的结果，这可以通过以下调整来完成上述代码:

Date.prototype.getWeek = function() {
 var firstday = new Date(this.getFullYear(),0,1);
 var today = new Date(this.getFullYear(),this.getMonth(),this.getDate());
 var dayOfYear = ((today - firstday + 86400000)/86400000);
 return Math.ceil(dayOfYear/7)
};
var today = new Date();
var currentWeekNumber = today.getWeek();
var jCurrentDynamic = CalcWeekRange(objArr,currentWeekNumber-1,currentWeekNumber);
var jPreviousDynamic = CalcWeekRange(objArr,currentWeekNumber -3,currentWeekNumber -2);
var jCurrentDisplayDynamic = jCurrentDynamic[0].displayAd_imp;
var jPreviousDisplayDynamic = jPreviousDynamic[0].displayAd_imp;
var resultDynamic = (jCurrentDisplayDynamic/jPreviousDisplayDynamic-1)*100;
console.log("resultDynamic ", resultDynamic);

我已经更新了小提琴，并添加了一个对象的实际当前周数34(只是一个副本33周的测试)，所以小提琴将停止工作下个星期:)

更新演示

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