InputMismatchException when entering integers multiple times

Question

I have seen other similar questions and didn't find any solution to my problem.

Just trying to scan 2 numbers and add them together:

Scanner input = new Scanner(System.in);
int number1;
int number2;
int sum;

System.out.print("First: ");
number1 = input.nextInt();
System.out.println("Second: ");
number2 = input.nextInt();

sum = number1 + number2;

System.out.println("The sum is " + sum);

the first one is printed out nicely and the next time it just crashes with IME... What am i doing wrong?

@Nomad You can't cast a string to an int. I guess you mean "parse to int" — Andy Turner, Apr 16 '15 at 12:01

Andy Turner · Answer 1 · 2015-04-16T12:43:47.490

1

Insert input.nextLine() after your first nextInt() call. nextInt() will leave behind the newline character.

edited Apr 16 '15 at 12:43

answered Apr 16 '15 at 11:44

Andy Turner

137,514
11
162
243

score 0 · Accepted Answer · answered Apr 16 '15 at 12:23

This question has been asked many times here including myself long ago.

When using scn.nextInt(), it still waits from input thus affecting all the inputs later on.

There are 2 approach to solve this problem.

Place a scn.nextLine() after your scn.nextInt();

System.out.print("First: ");
number1 = input.nextInt(); input.nextLine();
System.out.println("Second: ");
number2 = input.nextInt(); input.nextLine();

Receive as String and parse to integer (I prefer this method)

System.out.print("First: ");
number1 = Integer.parseInt(input.nextLine());
System.out.println("Second: ");
number2 = Integer.parseInt(input.nextLine());

If you have some experiences in C#, they expect you do to it with the 2nd method as well.

InputMismatchException when entering integers multiple times

2 Answers2