【发布时间】：2021-06-23 00:44:36
【问题描述】：
import java.util.Scanner;
import java.util.Random;
import java.util.Arrays;
public class midterm {
static Scanner scanner = new Scanner(System.in);
public static void main(String[] args) {
Account myAccount = new Account();
int user_choice;
do{
System.out.println();
System.out.println("1) New Billing");
System.out.println("2) Add Existing Billing");
System.out.println("3) View Billing Account ID");
System.out.println("4) View By Date");
System.out.println("5) Update Existing Billing");
System.out.println("6) Delete Billing Account");
System.out.println("7) Display All Account");
System.out.println("8) Exit");
System.out.println();
System.out.print("Enter choice [1-8]: ");
user_choice = scanner.nextInt();
switch (user_choice) {
case 1:
String id;
System.out.print("Enter Billing Code: ");
String bc = scanner.next();
System.out.print("Enter Billing Date(dd/mm/yyyy): ");
String bd = scanner.next();
System.out.print("Enter Customer Name: ");
String customerName = scanner.nextLine();
System.out.print("Enter Customer Address: ");
String customerAddress = scanner.nextLine();
System.out.print("Enter Customer Number: ");
String customerNumber = scanner.nextLine();
System.out.print("Enter Period To: ");
String periodT = scanner.nextLine();
System.out.print("Enter Period From: ");
String periodF = scanner.nextLine();
System.out.print("Enter Present Reading: ");
double presentR = scanner.nextDouble();
System.out.print("Enter Previous Reading: ");
double previousR = scanner.nextDouble();
System.out.print("Enter Previous Balance: ");
double previousB = scanner.nextDouble();
//myAccount.openNewAccount(id,bc,bd,customerName,customerAddress,customerNumber,periodT,periodF,presentR,previousR,previousB);
System.out.println("Account was created and it has the following number: " + myAccount.openNewAccount(id,bc,bd,customerName,customerAddress,customerNumber,periodT,periodF,presentR,previousR,previousB));
break;
case 7:
System.out.println("Enter a account number");
int anum = scanner.nextInt();
}
}while(user_choice!='6');
}
static class Account{
private userAccount[] account;
private int numOfAccounts = 10;
public Account(){
account = new userAccount[10];
numOfAccounts = 0;
}
```
这是存在问题的部分，它第一次工作但现在它不工作，我对构造函数和类是如何工作的新手。它说需要：未找到参数：字符串，字符串，字符串，字符串，字符串，字符串，字符串，字符串，双精度，双精度，双原因：实际和形式参数列表的长度不同，我只是希望它传递输入的数据randomStr 给出一个随机帐户号 ```
public int openNewAccount(String id,String bc,String bd,String customerName,String customerAddress,String customerNumber,String periodT,String periodF,double presentR,double previousR,double previousB){
int min = 1000;
int max = 9999;
int randomStr = (int)(Math.random() * (max - min + 1) + min);
userAccount randomStr = new userAccount(id,bc,bd,customerName,customerAddress,customerNumber,periodT,periodF,presentR,previousR,previousB);
account[numOfAccounts] = randomStr;
numOfAccounts++;
return randomStr.getAccountNum();
}
}
this is my userAccount class where the user is stored, it worked the first time but now it doesn't
static class userAccount{
private int accountNum;
private String id;
private String bc;
private String bd;
private String customerName;
private String customerAddress;
private String customerNumber;
private String periodT;
private String periodF;
private double presentR;
private double previousR;
private double previousB;
private static int noOfAccounts=0;
public int userAccount(String idN,String bcN,String bdN,String customerName1,String customerAddress1,String customerNumber1,String periodT1,String periodF1,double presentR1,double previousR1,double previousB1){
id = idN;
bc = bcN;
bd = bdN;
customerName = customerName1;
customerAddress = customerAddress1;
customerNumber = customerNumber1;
periodT = periodT1;
periodF = periodF1;
presentR = presentR1;
previousR = previousR1;
previousB = previousB1;
noOfAccounts++;
accountNum = noOfAccounts;
}
public int getAccountNum(){
return accountNum;
}
}
}
this is not yet finished just checking if it works, ive been tweaking this but cant really understand why it says my randomStr is already defined.
这是它在编译器中显示的错误。
midterm.java:80: error: variable randomStr is already defined in method openNewAccount(String,String,String,String,String,String,String,String,double,double,double)
userAccount randomStr = new userAccount(id,bc,bd,customerName,customerAddress,customerNumber,periodT,periodF,presentR,previousR,previousB);
^
midterm.java:80: error: constructor userAccount in class userAccount cannot be applied to given types;
userAccount randomStr = new userAccount(id,bc,bd,customerName,customerAddress,customerNumber,periodT,periodF,presentR,previousR,previousB);
^
required: no arguments
found: String,String,String,String,String,String,String,String,double,double,double
reason: actual and formal argument lists differ in length
2 errors
【问题讨论】：
-
public int userAccount不是构造函数，它是一个返回int的方法。你有两个randomStr，一个是int，一个是userAccount，也不是顾名思义的String。并且请以大写字母开头类（和一般类型），否则它们很难与变量区分开来。因不理解两个非常明显的编译器错误而投反对票。
标签： java arrays class methods constructor