好的,我已经再次使用此代码了。
我需要输入一个不允许用户输入0的异常(因为你以后不能将0除以)并且用户不能输入字母字符。我试图显示消息,忽略错误的输入,并循环以允许用户再次尝试,直到他们输入可接受的数字。
这就是我所拥有的:
package exceptionhandler;
/**
*
* @author Sarah
*/
import java.util.Scanner;
public class ExceptionHandler {
/**
* @param args
* the command line arguments10 10
*/
public static void main(String[] args) throws NumberFormatException {
Scanner in = new Scanner(System.in);
Scanner input = new Scanner(System.in);
System.out.print("Please enter ten values:");
System.out.println();
// Input the data into array from the user.
double[ ] digit = new double[11];
int sum = 0;
//Declare an array
try
{
for (int i = 1; i < digit.length; i++) {
System.out.print("Value " + i + ": ");
digit[i] = (double)in.nextInt();
sum += (int)digit[i];
}
catch (NumberFormatException e)
{
System.out.println("You Can Only Enter Numbers!");
}
}
System.out.println("Total Values in Array:"+ sum);
// Calculate the sum and print the total
System.out.println();
System.out.println("Would you like to divide the values?");
System.out.println("Yes or No to Exit the Program");
String a = input.next();
if(a.equalsIgnoreCase("yes")){
double [] divisionResult = new double[digit.length / 2];
//Division array declared
for (int i = 1; i < digit.length; i += 2)
{
double result = digit[i];
if (result > digit[i + 1])
result = result / digit[i + 1];
else {
result = digit[i + 1] / result;
}
divisionResult [i / 2] = result;
System.out.println(result);
}
}
else if(a.equalsIgnoreCase("no")){
System.exit(0);
}
}
}
我已经尝试声明抛出异常然后尝试了try..catch。但它并没有认识到捕获并试图互相交谈......所以我知道我做错了什么,但我不知道应该去哪里。
异常是否在正确的位置?我应该做别的吗?我的异常写错了吗?那么我怎样才能继续防止输入零和重新抛出?
帮助?
答案 0 :(得分:0)
在输入字符时应该InputMismatchException
而不是NumberFormatException
来捕获异常,如果用户输入0和deduct 1
,则需要检查 0 for-loop的当前索引让用户再试一次。
<强>样品:强>
for (int i = 1; i < digit.length; i++) {
try {
System.out.print("Value " + i + ": ");
digit[i] = (double) in.nextInt();
sum += (int) digit[i];
if(digit[i] == 0.0)
{
System.out.println("You cant enter 0: try again");
--i;
}
} catch (InputMismatchException e) {
System.out.println("You Can Only Enter Numbers!");
--i;
in.nextLine(); //to consume the character
}
}
<强>结果:强>
Please enter ten values:
Value 1: 0
You cant enter 0: try again
Value 1: asd
You Can Only Enter Numbers!
Value 1: