Question

为什么jGrasp没有意识到我的构造函数需要两个双打？特别是，因为我只有一个构造函数。

这是我的班级：

public class SavingsAccount{
   private double balance;
   private double interestRate;
   private double lastInterest;

   public void SavingsAccount(double bal, double intRate){

      balance = bal;
      interestRate = intRate;
   }

//Other methods

}

在我的main方法中，我尝试实例化它：

double bal = 500.00;
double intRate = .002;
SavingsAccount savings = new SavingsAccount(bal, intRate);

但是当我尝试运行这是jGrasp时，它会显示一个错误，即

TestSavingsAccount.java:9: error: constructor SavingsAccount in class SavingsAccount cannot be applied to given types;
  SavingsAccount savings = new SavingsAccount(bal, intRate);
                           ^
required: no arguments
found: double,double
reason: actual and formal argument lists differ in length
1 error

Answer 1

你的“构造函数”有一个void字，这使它成为一种方法。构造函数不能具有返回类型。你需要删除它：

public SavingsAccount(double bal, double intRate){

      balance = bal;
      interestRate = intRate;
   }

Answer 2

     public void SavingsAccount(double bal, double intRate){
      balance = bal;
      interestRate = intRate;
     }

应该是：

     public SavingsAccount(double bal, double intRate){
      balance = bal;
      interestRate = intRate;
     }

您声明了一个向签名添加void的方法。

Java构造函数参数不匹配

2 个答案: