提问人：Corey Aoi Senkō Ausby 提问时间：9/14/2015 更新时间：9/14/2015 访问量：176
当用户可以输入 int 和 double 时添加两个数字
Adding two numbers when the user can enter an int and double
问：
我需要当用户输入例如 4 和 6.5 时运行程序，反之亦然。 我只有在它或它尝试同时为两者运行它时才运行if else，我得到这样的错误代码：
Exception in thread "main" java.util.InputMismatchException
at java.util.Scanner.throwFor(Unknown Source)
at java.util.Scanner.next(Unknown Source)
at java.util.Scanner.nextInt(Unknown Source)
at java.util.Scanner.nextInt(Unknown Source)
at class2.AddTwoNumbers.main(AddTwoNumbers.java:28)
如能提供任何协助，将不胜感激
public class AddTwoNumbers {
public static void main(String[] args) {
Scanner inputSource = new Scanner(System.in);
Scanner runAgain = new Scanner(System.in);
int input1, input2, result;
double input3, input4, result2;
String answer = null;
do {
System.out.println("Please enter two numbers: ");
if(inputSource.hasNextInt()) {
input1 = inputSource.nextInt();
input2 = inputSource.nextInt();
result = input1 + input2;
System.out.println("The sum of " + input1 + " and " + input2 + " is " + result);
} else if (!inputSource.hasNextInt()){
input3 = inputSource.nextDouble();
input4 = inputSource.nextDouble();
result2 = input3 + input4;
System.out.println("The sum of " + input3 + " and " + input4 + " is " + result2);
} else if (inputSource.hasNextInt() || inputSource.hasNextDouble()){
input1 = inputSource.nextInt();
input3 = inputSource.nextDouble();
result2 = input1 + input3;
System.out.println("The sum of " + input1 + " and " + input3 + " is " + result2);
}
System.out.println("Do you want to run this again? Enter Y for Yes or N for No: ");
answer = runAgain.next();
} while (answer != "N");
inputSource.close();
}
}
答：
0赞
Eran
9/14/2015
#1
在这种情况下，使用 读取输入更有意义。这适用于输入和输入。double number = Double.parseDouble(inputSource.nextLine());intdouble
您的代码变得如此简单：
double input1 = Double.parseDouble(inputSource.nextLine());
double input2 = Double.parseDouble(inputSource.nextLine());
double result = input1 + input2;
除此之外，更改为 .while (answer != "N");while (!answer.equals("N"));
-1赞
Rustam
9/14/2015
#2
use 方法而不是并将其解析为 double，这将适用于 and 类型nextLine()nextInt()intdouble
double result;
double input1=Double.parseDouble(inputSource.nextLine());
double input2=Double.parseDouble(inputSource.nextLine());
result=input1+input2;
并且还随while (answer != "N");while (!answer.equals("N"));// since your are comparing string not character
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