java - Java新手，尝试编写一个基本程序但遇到问题

Question

这个问题已经有答案了:

Are fields initialized before constructor code is run in Java? (5 个回答)

已关闭 7 年前。

我正在尝试使用用户输入(几乎只是我自己的输入)创建一个基本计算程序并处理非常少的计算。但我似乎无法让计算返回。我正在这个文件中进行所有计算:

public class Drug {

private double goalForQuarter = 3716.0;
private double currentScripts;
private double currentDaysIntoQuarter;
private double scriptsNeededDaily100 = goalForQuarter / currentDaysIntoQuarter;
private double scriptsNeededDaily105 = scriptsNeededDaily100 * 1.05;
private double scriptPercentage = currentScripts / scriptsNeededDaily100;


public Drug () {

}

public Drug (double currentScripts) {
    this.currentScripts = currentScripts;
}

public Drug (double currentScripts, double currentDays){
    this.currentScripts = currentScripts;
    this.currentDaysIntoQuarter = currentDays;
}

public double calcDrug100 (){

    return this.scriptPercentage;
}


}

这个主程序在这里运行:

导入java.util.Scanner;

public class Main {

    public static void main(String[] args){
        Scanner reader = new Scanner(System.in);

        System.out.print("Input number of days into Quarter: ");
        double days = Integer.parseInt(reader.nextLine());
        System.out.println("Input current number of Scripts: ");
        double scripts = Integer.parseInt(reader.nextLine());


        Drug drug1 = new Drug(scripts, days);

        System.out.println(drug1.calcDrug100());

    }

}

即使有用户输入，我也会打印出 0.0 。我已经使用了我的变量和方法，但似乎无法使其工作。任何帮助将不胜感激!

Answer 1

scriptPercentage 是一个字段。当 currentScripts 或 scriptsNeededDaily100 执行更新时，它不会自动更新。

public double calcDrug100 (){
    this.scriptPercentage = this.currentScripts / this.scriptsNeededDaily100;
    return this.scriptPercentage;
}