Question

这是我的代码： -

公共课程计划{

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]);
            }
        }   
    }

从中提取代码的下一课： -

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;
}

}

编译程序时出现问题： -

必需：double，double，int，int

发现：String，String，String，String

原因：实际参数String不能通过方法调用转换转换为double

Program.java:19：错误：类CompoundInterestCalculator中的方法continuousCompound不能应用于给定的类型;

Answer 1

首先，在使用.equals比较对象时比较内存地址时，将String与==进行比较而不是==。

因此(args[0] == "interest")成为(args[0].equals("interest"))

其次，您将String传递给声明为

的方法

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

通过此次通话

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，对呼叫runCal.continuousCompound(args[2], args[3], args[4]);

应用相同的内容

必需：Double，int Found：String，String

1 个答案: