必需：Double，int 找到：String，String

Question

这是我的代码：-

公开课程序{

public static void main(String[] args) {
    if (args[0] == "interest"){
        public CompoundInerestCalculator(){
            CompoundInterestCalculator runCal = new CompoundInterestCalculator();
            if (args[1] == "annual"){
                runCal.compoundAnnually(args[2], args[3], args[4], args[5]);

            }

            else {
                args[1] = "continuous";
                runCal.continuousCompound(args[2], args[3], args[4]);
            }
        }   
    }

提取代码的下一个类：-

公共类 CompoundInterestCalculator {

// Calculation for Annual Compound Interest
public BigDecimal compoundAnnually(double principal, double rate, int periods, int years) {
    double finalAmount = principal * Math.pow( 1 + ( rate / periods), years * periods);
    double compoundInterest = finalAmount - principal;
    BigDecimal finalInterest = new BigDecimal(compoundInterest);
    System.out.print(finalInterest);
        return finalInterest;
}

// Calculation for Continuous Compound Interest
public BigDecimal continuousCompound(double principal, double rate, int years) {
    double finalAmount = principal * Math.pow( Math.E, rate * years);
    double compoundInterest = finalAmount - principal;
    BigDecimal finalInterest = new BigDecimal(compoundInterest);
    System.out.print(finalInterest);
        return finalInterest;
}

}

这是我编译程序时遇到的问题：-

必需：双精度、双精度、整数、整数

找到：字符串、字符串、字符串、字符串

原因：实参String无法通过方法调用转换为double

Program.java:19: 错误：CompoundInterestCalculator 类中的方法 ContinuousCompound 不能应用于给定类型；

Answer 1

首先，比较 String 和 .equals 而不是 ==，因为您在使用 == 比较对象时比较内存地址。

所以(args[0] == "interest")变成(args[0].equals("interest"))

其次，您将 Strings 传递给声明为

的方法

compoundAnnually(double principal, double rate, int periods, int years)

有了这个电话

runCal.compoundAnnually(args[2], args[3], args[4], args[5]);

您需要将它们解析为正确的类型...

runCal.compoundAnnually(Double.parseDouble(args[2]), Double.parseDouble(args[3]), Integer.parseInt(args[4]), Integer.parseInt(args[5]))

第三，同样适用于通话runCal.continuousCompound(args[2], args[3], args[4]);