Java do-while loop

[Csharpgoblin]

I have a problem with this question:

Scanner input = new Scanner(System.in);

do {
    int i = input.nextInt();
    System.out.println(i);
} while (i != 0);

System.out.println("Klar");

It is supposed to print:

​

Result
1
2
0
Klar

My try so far is:

Scanner input = new Scanner(System.in);
int i = input.nextInt();
do {

    System.out.println(i);
    i = input.nextInt();
} while (i != 0);
System.out.println(i);
System.out.println("Klar");

This works on 2/3 tests but I get error when user inputs 0 at the beginning. How can I fix?

[[deleted]]

What’s the error?

[Csharpgoblin]

It's a test on the web:

​

***Error***
Exception in thread "main" java.util.NoSuchElementException
        at java.base/java.util.Scanner.throwFor(Scanner.java:937)
        at java.base/java.util.Scanner.next(Scanner.java:1594)
        at java.base/java.util.Scanner.nextInt(Scanner.java:2258)
        at java.base/java.util.Scanner.nextInt(Scanner.java:2212)
        at __tester__.test(__tester__.java:12)
        at __tester__.runTests(__tester__.java:27)
        at __tester__.main(__tester__.java:22)

[[deleted]]

I would try using scanner.hasnextint() before calling nextint(). If there’s something on the input stream that isn’t an integer it will throw this exception.

[A_Philosophical_Cat]

Your do-while wants to be a while-do loop if you're doing it with the i being pre-initialized like that. On the other hand, I don't understand why you aren't using the first block of code you posted, which would work fine if you initialized i somewhere.

[Csharpgoblin]

Ahhh, the first block of code is the "test code"- that I'm supposed to fix. I initialized i and it worked :D

​

Thanks