Java.util.Scanner 错误

Question

我正在编写一个程序，根据用户提供的一些输入返回 future 值

import java.util.Scanner; //import utility package, scanner class
import java.lang.Math; //import language package, math class 
class InvestmentCalculation

{
   public static void main(String[] args) 

   {

      Scanner s = new Scanner(System.in);

      //Principle Value Input
      System.out.print("Enter principle deposit: ");
      int p = s.nextInt ();

      //Interest Rate Input
      System.out.print("Enter annual interest rate: ");
      int r = s.nextInt ();

      double fv = p * Math.pow( (1.0 + r/100), 10);  


      //operation print
      System.out.println("Your investment will be worth: " + fv);
   }
} 

当我运行该程序时，输入费率后会出现以下错误:

Exception in thread "main" java.util.InputMismatchException
    at java.util.Scanner.throwFor(Scanner.java:864)
    at java.util.Scanner.next(Scanner.java:1485)
    at java.util.Scanner.nextInt(Scanner.java:2117)
    at java.util.Scanner.nextInt(Scanner.java:2076)
    at InvestmentCalculation.main(Addition.java:20)

Answer 1

这是因为您输入的汇率可能是 double 的，因此输入不正确。

注意:JavaDocs 中的 InputMismatchException内容如下:

Thrown by a Scanner to indicate that the token retrieved does not match the pattern for the expected type, or that the token is out of range for the expected type.

修复方式:

//Interest Rate Input
System.out.print("Enter annual interest rate: ");
double r = s.nextDouble();