我正在为贷款系统创建HomeLoans和CarLoans。需要能够创建用户想要的数量。 switch语句用于菜单。我当前的问题是，当我创建一份房屋贷款并返回菜单，然后再创建另一个贷款时，它迫使我进行了2笔贷款。我想是因为我的Homecount ++。然后，当我查看贷款时，它只记住前两个，而不是第一个。我如何继续创建借贷并将其添加到阵列中，而又不会因切入和退出switch语句而丢失数据？
public class TestingClasses {
private static Loan getInfo(Scanner scan, char c){
System.out.println("Please enter your Name: ");
String nameOf = scan.next();
System.out.println("Please enter an ID Number: ");
String id_Number = scan.next();
System.out.println("Please enter a Loan Number: ");
String loan_Number = scan.next();
System.out.println("Please enter the amount of the Loan: ");
double loan_Amount = scan.nextDouble();
System.out.println("Please enter your desired Interest Rate: ");
double interest_rate = scan.nextDouble();
while(interest_rate > 100.00){ //Check valid number
System.out.println("Invalid percentage. Please enter 0.00 - 100.00");
interest_rate = scan.nextDouble();
}
System.out.println("How long will you like the loan? Please enter 1-30.");
int term = scan.nextInt();
while(term > 30){ // Check for valid number
System.out.println("Invalid number of years. Please enter 1-30.");
term = scan.nextInt();
}
System.out.println("Current balance is being set to the Loan amount. \n");
double c_balance = loan_Amount;
if(c == 'H'){
System.out.println("Please enter an address for the Home: ");
String address = scan.next();
return new HomeLoan(nameOf,id_Number,loan_Number,loan_Amount,
interest_rate,term,c_balance,address);
}
if(c == 'C'){
System.out.println("Please enter the Make of the car: ");
String make = scan.next();
System.out.println("Please enter the Model of the car: ");
String model = scan.next();
System.out.println("Please enter the Year of the car: ");
String year = scan.next();
return new CarLoan(nameOf,id_Number,loan_Number,loan_Amount,
interest_rate,term,c_balance,make,model,year);
}
else
return null;
}
public static void main(String[] args) throws IOException {
int CarCount=0,HomeCount = 0;
int j = 0;
HomeLoan HL[]=null;
CarLoan CL[]=null;
Scanner scan = new Scanner(System.in);
int menuChoice = 0;
char c;
HL= new HomeLoan[60];
String mainMenu = ("Select a choice from the menu: \n"
+ "1. Create HomeLoan\n"
+ "2. Create CarLoan\n"
+ "3. Make Payment\n"
+ "4. Check Balances\n"
+ "5. List of HomeLoans\n"
+ "6. List of CarLoans\n"
+ "7. Amortization Report\n"
+ "8. Exit");
System.out.println("Welcome to the Loan system! \n");
do{
System.out.println(mainMenu);
menuChoice = scan.nextInt();
while (menuChoice < 1 || menuChoice > 8) {
System.out.print("\nError! Incorrect choice.\n");
System.out.println(mainMenu);
menuChoice = scan.nextInt();
}
switch (menuChoice) {
case 1: {
c = 'H';
// Add 1 to HomeCount
for(; j == HomeCount; j++){
HL[j]=(HomeLoan)getInfo(scan,c);
System.out.println(HL[j].getHomeLoanNumber());
}
HomeCount++;
break;
}
case 2: {
c = 'C';
CarCount++; // Add 1 to Car Count
CL = new CarLoan[CarCount];
for(int j = 0; j < CarCount; j++){ //Loop through loans
CL[j]=(CarLoan)getInfo(scan,c);
System.out.println(CL[j].getCarLoanNumber());
}
break;
}
case 5: {
for(int k=0; k < HomeCount; k++){
System.out.println(HL[k]+ "\n");
}
break;
}
}
}while(menuChoice != 8); //ending do while loop
}//end main
}//end class
最佳答案
每次创建新数组时，都将删除前一个数组（当然，它不会被删除，但是对它的所有引用都会丢失，因此它也可能已被删除）。更好的解决方案是使用ArrayList<Loan>而不是数组，*在循环之前创建一次，然后根据需要简单地将项目添加到列表中。将ArrayList视为可以动态扩展或缩小大小的数组。
否则，如果必须使用数组，则考虑在声明数组时创建一次数组，并在创建数组时为其提供足够的项，以免空间不足。
关于java - switch语句期间的增量计数，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/20036759/