Java 银行利息

我想做一个程序，用原理、利率和年数计算账户的复利。我试着用对话框/程序有输出，如果让原理累积，则返回投资

我被困在计算部分，请帮忙

package firstAssignment;

import java.util.Scanner;

import javax.swing.JOptionPane;

public class thinkingQuestion {

public static void main(String[] args) {

//Banking program that asks user for the amount of money they wish to invest in a 
//compound interest account (principle), the interest rate (percent value) and the time frame (years).

    Scanner in= new Scanner(System.in);

    String principle, interestVal, years;
    int newPrinciple,newYears;
    double total;

        principle=JOptionPane.showInputDialog("How much money would you like to invest?");

        interestVal=JOptionPane.showInputDialog("What's the interest rate?");   

        years=JOptionPane.showInputDialog("How many years?");

        //convert from String to integer

        newPrinciple=Integer.parseInt(principle);
        newYears=Integer.parseInt(years);

        double newInterestVal=Integer.parseInt(interestVal);

        total=JOptionPane.PLAIN_MESSAGE(newPrinciple*Math.pow(1+ newInterestVal, newYears), newYears);

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我删除了您不需要的somo变量，我认为主要问题在于显示消息的java语法。在这里您可以看到一个教程：

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我特别专注于合计部分，因为它不允许我在问题中使用利息公式。合计=newPrinciple*Math.pow（（1+newInterestVal），newYears）；JOptionPane.showMessageDialog（null，total+“”，“total”，JOptionPane.INFORMATION\u MESSAGE）；此外，您还必须输入复利周期数，n。这里我假设n=1它显示了将字符串转换为int的错误，特别是第31行它在测试它时显示了错误，它说是将字符串转换为双精度或int行。您使用的是哪个版本的java？eclipse kepler，我的学校不允许我们使用更高版本在窗口菜单上转到preferences>java>compiler。告诉我哪一个是编译器符合性级别编译器级别是1.4

import javax.swing.JOptionPane;

public class InterestBanking {

    public static void main(String[] args) {

        // Banking program that asks user for the amount of money they wish to
        // invest in a
        // compound interest account (principle), the interest rate (percent
        // value) and the time frame (years).

        String principle, interestVal, years;
        float newPrinciple, newYears;

        principle = JOptionPane.showInputDialog("How much money would you like to invest?");

        interestVal = JOptionPane.showInputDialog("What's the interest rate?");

        years = JOptionPane.showInputDialog("How many years?");

        // convert from String to integer

        newPrinciple = Float.parseFloat(principle);
        newYears = Float.parseFloat(years);

        double newInterestVal = Float.parseFloat(interestVal);

        //You could change your calculation here if this isn't the need formula
        double interest = newPrinciple * Math.pow(1 + newInterestVal, newYears);

        //you were assigning the result to a total variable. That's not neccesary
        JOptionPane.showMessageDialog(null, "Interest:" + NumberFormat.getCurrencyInstance(new Locale("en", "US")).format(interest) + " In years: " + newYears);
    }
}