在 React 中计算总价

Question

所以这是我第一次尝试 React。我必须计算预订的（总）价格。

保留价格由以下几个因素决定：

船长：每米 1.25 欧元
人数：每人€1
电费：每天 1.25 欧元

假设船长 10 米，船上有 2 个人用电。他们待了 2 天。计算如下：

船长(10) * 1.25 * 2 = 25
人数(2) * 1 * 2 = 4
用电（真）= 1.25 * 2 = 2.5
total_price = 25 欧元 + 4 欧元 + 2.5 欧元 = 21.5 欧元

我尝试在我的代码中实现它，如下所示：

import React, { Component } from 'react'
import BoatForm from "./BoatForm";
import StayForm from "./StayForm";

export default class PriceCalculator extends Component {
    /**
     * So, we created a form for the customers so that they can register their boat.
     * Now we want to let them know how much their reservation costs.
     * The size of the boat, amount of people, amount of days and use of electricity are all parameters.
     */

    constructor(props) {
        super(props)
        this.state = {
            boat_length: '',
            amount_of_people: '',
            arrival_date: '',
            leave_date: '',
            use_of_electricity: '',
            box_number: ''
        }
    }

    /**
     * We use date fields in our form to define the stay date of the customer.
     * That means we have to calculate the days ourselves.
     */

    calculateStayTime() {
        const ArrivalDate = new Date(this.state.arrival_date);
        const LeaveDate = new Date(this.state.leave_date);
        // calculate difference
        const DiffTime = Math.abs(LeaveDate - ArrivalDate);
        const DiffDays = Math.ceil(DiffTime / (1000 * 60 * 60 * 24));
        let AmountOfDays = DiffDays;
        return AmountOfDays;
    }

    /**
     *  Prices per day:
     *  - Price per meter: 1,25
     *  - Price per person: 1
     *  - Price for using electricity: 1,25
     */

    calculatePrice() {
        const BoatLength = this.state.boat_length;
        const meter_price = 1.25;
        const Persons = this.state.amount_of_people;
        const persons_price = 1;

        let price_per_day = BoatLength * meter_price + Persons * persons_price;


        const electricity_price = 1.25;
        const use_of_electricity = true;
        // ? = if statement
        price_per_day = price_per_day + (use_of_electricity ? electricity_price : 0);
        // const total_price = price_per_day * AmountOfDays;
    }

}

我很难将变量从 calculateStayTime() 传递到 calculatePrice()。任何人都可以帮助我如何将我的计算公式化为 React.JS？

Answer 1

您需要在calculatePrice中使用calculateStayTime的结果。您可以将停留时间值分配给一个变量，但我可能只替换最后一行：// const total_price = price_per_day * AmountOfDays; 可以替换为 const total_price = price_per_day * this.calculateStayTime();，这应该可以满足您的需求。

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