Question

这段JAVA代码哪儿出问题了？ 为什么结果不对？

新手啊 一共只有5分了 全给了 不好意思啊
public class Loan {
private double annualInterestRate;
private int numberOfYears;
private double loanAmount;
private java.util.Date loanDate;

public Loan() {
this(7.5, 30, 100000);
}

public Loan(double annualInterestRate, int numberOfYears, double loanAoumt) {
this.annualInterestRate = annualInterestRate;
this.numberOfYears = numberOfYears;
this.loanAmount = loanAmount;
loanDate = new java.util.Date();
}

public double getannualInterestRate() {
return annualInterestRate;
}

public void setannualInterestRate(double annualInterestRate) {
this.annualInterestRate = annualInterestRate;
}

public int getNumberOfYears() {
return numberOfYears;
}

public void setNumberOfYears(int numberOfYears) {
this.numberOfYears = numberOfYears;
}

public double getLoanAmount() {
return loanAmount;
}

public double getMonthlyPayment() {
double monthlyInterestRate = annualInterestRate / 1200;
return loanAmount
* monthlyInterestRate
/ (1 - (Math.pow(1 / (1 + monthlyInterestRate),
numberOfYears * 12)));
}
public java.util.Date getLoanDate(){
return loanDate;
}
public double getTotalPayment(){
return getMonthlyPayment() * numberOfYears * 12;
}
}
----------------------------
import javax.swing.JOptionPane;

public class TestLoan {

public static void main(String[] args) {
String annualInterestRateString = JOptionPane
.showInputDialog("Enter yearly interest rate,for example 8.25:");
double annualInterestRate = Double
.parseDouble(annualInterestRateString);
String numberOfYearsString = JOptionPane
.showInputDialog("Enter number of years as an integer,\nfor example 5:");
int numberOfYears = Integer.parseInt(numberOfYearsString);
String loanString = JOptionPane
.showInputDialog("Enter loan amount,for example 120000.95:");
double loanAmount = Double.parseDouble(loanString);
Loan loan = new Loan(annualInterestRate, numberOfYears, loanAmount);
double monthlyPayment = (int) (loan.getMonthlyPayment() * 100) / 100.0;
double totalPayment = (int) (loan.getTotalPayment() * 100) / 100.0;
String output = "The loan was created on "
+ loan.getLoanDate().toString() + "\nThe monthly paymen is "
+ monthlyPayment + "\nThe total payment is " + totalPayment;
JOptionPane.showMessageDialog(null, output);

}

}
输了信息进去 结果输出来都是0 看了很久也不知道哪儿错了

Answer 1

public class Loan {
private double annualInterestRate;
private int numberOfYears;
private double loanAmount;
private java.util.Date loanDate;

/*public Loan() {
//this(7.5, 30, 100000);
}*/

public Loan(double annualInterestRate, int numberOfYears, double loanAmount) {
this.annualInterestRate = annualInterestRate;
this.numberOfYears = numberOfYears;
this.loanAmount = loanAmount;//注意这个拼写和参数的拼写。。。。
loanDate = new java.util.Date();
}

public double getannualInterestRate() {
return annualInterestRate;
}

public void setannualInterestRate(double annualInterestRate) {
this.annualInterestRate = annualInterestRate;
}

public int getNumberOfYears() {
return numberOfYears;
}

public void setNumberOfYears(int numberOfYears) {
this.numberOfYears = numberOfYears;
}

public double getLoanAmount() {
return loanAmount;
}

public double getMonthlyPayment() {
double monthlyInterestRate = annualInterestRate / 1200;
return loanAmount
* monthlyInterestRate
/ (1 - (Math.pow(1 / (1 + monthlyInterestRate),
numberOfYears * 12)));
}
public java.util.Date getLoanDate(){
return loanDate;
}
public double getTotalPayment(){
return getMonthlyPayment() * numberOfYears * 12;
}
}

如果都是零，首先考虑的问题就是参数传错了。。。

Answer 2

这个变量名也太长了吧

Answer 3

public Loan(double annualInterestRate, int numberOfYears, double loanAoumt) { //这里参数名字错了
this.annualInterestRate = annualInterestRate;
this.numberOfYears = numberOfYears;
this.loanAmount = loanAmount;
loanDate = new java.util.Date();
}