问为什么我的index.js代码没有办法计算出我最后要求计算出来的结果？

我的代码如下，不知道为什么最后的FinalexpectedPaybackTime结果始终无法自动计算出来，特此求助，感谢帮助。

// index.js

// 获取小程序实例

const app = getApp();

Page({

  data: {

    showInputModal: false,

    inputModalTitle: '',

    inputValue: '',

    inputType: 'text',

    inputCallback: null,

    maintenanceFee: 0,

    operatorCost: 0,

    immunohistochemistryGrowthRate: 0,

    detectionSystemPrice: 0,

    detectionSystemCost: 0,

    dailySlideCount: 0,

    exchangeRate: 0,

    instrumentPriceUSD: 0,

    menuItems: ['无','BOND 试剂政策', '2023 BOND 政策', 'BOND 试剂政策+2023 BOND 政策'], // 下拉菜单选项

    selectedMenuItem: '', // 当前选择的选项

    isMenuOpen: false, // 下拉菜单是否打开

    finalexpectedPaybackTime: 0,

    machineDiscount: 0,

},

toggleMenu : function () {

this.setData({

      isMenuOpen: !this.data.isMenuOpen

});

},

selectMenuItem: function (e) {

const { value } = e.currentTarget.dataset;

this.setData({ selectedMenuItem: value, isMenuOpen: false

});

},

onInputModalCancel() {

this.setData({ showInputModal: false });

},

onInputModalConfirm() {

this.data.inputCallback(this.data.inputValue);

this.setData({ showInputModal: false });

},

onInputChange(e) {

this.setData({ inputValue: e.detail.value });

},

instrumentPriceUSDInput: function (e) {

const instrumentPriceUSD = parseFloat(e.detail.value);

this.setData({ instrumentPriceUSD: instrumentPriceUSD });

this.calculateResults();

},

machineDiscountInput: function (e) {

const machineDiscount = parseFloat(e.detail.value);

this.setData({ machineDiscount: machineDiscount });

this.calculateResults();

},

dailySlideCountInput: function (e) {

const dailySlideCount = parseFloat(e.detail.value);

this.setData({ dailySlideCount: dailySlideCount });

this.calculateResults();

},

detectionSystemCostInput: function (e) {

const detectionSystemCost = parseFloat(e.detail.value);

this.setData({ detectionSystemCost: detectionSystemCost });

this.calculateResults();

},

detectionSystemPriceInput: function (e) {

const detectionSystemPrice = parseFloat(e.detail.value);

this.setData({ detectionSystemPrice: detectionSystemPrice });

this.calculateResults();

},

immunohistochemistryGrowthRateInput: function (e) {

const immunohistochemistryGrowthRate = parseFloat(e.detail.value);

this.setData({ immunohistochemistryGrowthRate: immunohistochemistryGrowthRate });

this.calculateResults();

},

operatorCostInput: function (e) {

const operatorCost = parseFloat(e.detail.value);

this.setData({ operatorCost: operatorCost });

this.calculateResults();

},

maintenanceFeeInput: function (e) {

const maintenanceFee = parseFloat(e.detail.value);

this.setData({ maintenanceFee: maintenanceFee });

this.calculateResults();

},

exchangeRateInput: function (e) {

const { value } = e.detail;

// 使用正则表达式替换输入值，只保留数字和小数点，并限制小数点后两位

const formattedValue = value.replace(/[^\d.]/g, '').replace(/\.(?=.*\.)/g, '').slice(0, 5);

this.setData({ exchangeRate: formattedValue });

},

calculateResults: function () {

const {

instrumentPriceUSD,

machineDiscount,

exchangeRate,

dailySlideCount,

immunohistochemistryGrowthRate,

maintenanceFee,

operatorCost,

detectionSystemPrice,

detectionSystemCost,

selectedMenuItem,

} = this.data;

const instrumentPriceRMB = instrumentPriceUSD * exchangeRate;

const instrumentPriceWithDiscount = instrumentPriceRMB * (1 - machineDiscount / 100);

const detectionSystemRev = detectionSystemPrice-detectionSystemCost;

const annualSlideCount = dailySlideCount * 21.75 * 12;

const FirstreturnUnits = Math.floor((annualSlideCount / 600) * 200);

const FIRSTexpectedPaybackTime = (instrumentPriceWithDiscount+maintenanceFee+operatorCost*2)/(((annualSlideCount*detectionSystemRev)+ ((annualSlideCount * (1+immunohistochemistryGrowthRate)-FirstreturnUnits) *detectionSystemRev))+FirstreturnUnits*detectionSystemRev);

if (selectedMenuItem === 'BOND 试剂政策') {

let SECONDexpectedPaybackTime = FIRSTexpectedPaybackTime;

const SecondreturnUnits = Math.floor((annualSlideCount * (1+immunohistochemistryGrowthRate) / 600) * 200);

while (SECONDexpectedPaybackTime > 1) {

SECONDexpectedPaybackTime = instrumentPriceWithDiscount + maintenanceFee + operatorCost * 2 -((annualSlideCount * (1 + immunohistochemistryGrowthRate) * (1 + immunohistochemistryGrowthRate)) - SecondreturnUnits) * detectionSystemRev + SecondreturnUnits * detectionSystemPrice / ((annualSlideCount * (1 + immunohistochemistryGrowthRate) * (1 + immunohistochemistryGrowthRate)) - SecondreturnUnits) * detectionSystemRev + SecondreturnUnits * detectionSystemPrice;

const ThirdreturnUnits = Math.floor((annualSlideCount * (1 + immunohistochemistryGrowthRate) * (1 + immunohistochemistryGrowthRate)/ 600 * 200));

let ThirdexpectedPaybackTime = SECONDexpectedPaybackTime;

while (ThirdexpectedPaybackTime > 1) {

ThirdexpectedPaybackTime = ((annualSlideCount * (1 + immunohistochemistryGrowthRate) * (1 + immunohistochemistryGrowthRate)) - SecondreturnUnits) * detectionSystemRev + SecondreturnUnits * detectionSystemPrice-((annualSlideCount * (1 + immunohistochemistryGrowthRate) * (1 + immunohistochemistryGrowthRate)) - SecondreturnUnits) * detectionSystemRev - SecondreturnUnits * detectionSystemPrice + maintenanceFee + operatorCost / (annualSlideCount * (1 + immunohistochemistryGrowthRate) * (1 + immunohistochemistryGrowthRate) * (1 + immunohistochemistryGrowthRate) - ThirdreturnUnits) * detectionSystemRev + ThirdreturnUnits * detectionSystemPrice;

const FourthreturnUnits = Math.floor((annualSlideCount * (1 + immunohistochemistryGrowthRate) * (1 + immunohistochemistryGrowthRate)* (1 + immunohistochemistryGrowthRate) / 600 * 200));

let FourthexpectedPaybackTime = ThirdexpectedPaybackTime;

while (FourthexpectedPaybackTime > 1) {

FourthexpectedPaybackTime = ((annualSlideCount * (1 + immunohistochemistryGrowthRate) * (1 + immunohistochemistryGrowthRate)) - SecondreturnUnits) * detectionSystemRev + SecondreturnUnits * detectionSystemPrice-((annualSlideCount * (1 + immunohistochemistryGrowthRate) * (1 + immunohistochemistryGrowthRate)) - SecondreturnUnits) * detectionSystemRev - SecondreturnUnits * detectionSystemPrice + maintenanceFee + operatorCost-(annualSlideCount * (1 + immunohistochemistryGrowthRate) * (1 + immunohistochemistryGrowthRate) * (1 + immunohistochemistryGrowthRate) - ThirdreturnUnits) * detectionSystemRev - ThirdreturnUnits * detectionSystemPrice + maintenanceFee + operatorCost / (annualSlideCount * (1 + immunohistochemistryGrowthRate) * (1 + immunohistochemistryGrowthRate) * (1 + immunohistochemistryGrowthRate) * (1 + immunohistochemistryGrowthRate) - FourthreturnUnits) * detectionSystemRev + FourthreturnUnits * detectionSystemPrice;

if (SECONDexpectedPaybackTime < 1) {

FinalexpectedPaybackTime = 2 + SECONDexpectedPaybackTime * 12;

} else if (ThirdexpectedPaybackTime < 1) {

FinalexpectedPaybackTime = 3 + ThirdexpectedPaybackTime * 12;

} else if (FourthexpectedPaybackTime < 1) {

FinalexpectedPaybackTime = 4 + FourthexpectedPaybackTime * 12;

}

this.setData({

                   FinalexpectedPaybackTime: FinalexpectedPaybackTime

});

}

}

}

}

}

});