在Java中的另一个类中返回类构造函数字符串

Question

I have a class loan which has a constructor that set a string totalpaymentamt

I also have another class loan test which has the main method and am using it to output the string

I have done

public class Loan {
    public Loan() {
        String totalpaymentamt = "\t toString() results" + this.toString(this.getDuration(),
            this.getInterestRate(),
            this.gettotalAmount()) + "  \n \t getNumberOfYears() results:" + this.getDuration() + " getInterestRate() results:" + this.getInterestRate() + "  getTotalAmount() results:" + this.gettotalAmount() + " getMonthlyPayment:" + this.getMonthlyPayment(this.getDuration(),
            this.getInterestRate(),
            this.gettotalAmount());
    }
}

The other class is

public Loan(int duration, double interestRate, double totalAmount) {
     this.totalpaymentamt = "\t toString() results" + this.toString(duration, interestRate, totalAmount)

     + "  \n \t getNumberOfYears() results:" + duration
         + " getInterestRate() results:" + interestRate + "  getTotalAmount() results:" + totalAmount + " getMonthlyPayment:" + this.getMonthlyPayment(duration, interestRate, totalAmount);

}

This doesnt return anything. I understand a constructor has no return statement, How can i return the results o the loan constructor to the Testloan class main method

Answer 1

A constructor doesn't return anything.

Also, In your TestLoan class, you're extending the Loan class, which you don't need to do.

If you change the loan class constructor to something like this:

public class Loan {
    private String totalpaymentamt;

    public Loan() {

        this.totalpaymentamt = "\t toString() results"
                + this.toString(this.getDuration(),
                        this.getInterestRate(),
                        this.gettotalAmount())
                + "  \n \t getNumberOfYears() results:"
                + this.getDuration()
                + " getInterestRate() results:"
                + this.getInterestRate()
                + "  getTotalAmount() results:"
                + this.gettotalAmount()
                + " getMonthlyPayment:"
                + this.getMonthlyPayment(this.getDuration(),
                        this.getInterestRate(),
                        this.gettotalAmount());

    }


    public String getTotalPaymentAmount() {
        return this.totalpaymentamt;
    }
}

And then, in TestLoan, you can do:

Loan loan = new Loan();
System.out.println("First Loan \n " + loan.getTotalPaymentAmount());