Why this code not working here and throw NoSuchElementException?

Question

import java.util.Scanner;
public class Program
{
public static void main(String[] args) {
Scanner in=new Scanner(System.in);
System.out.println("Insert Number");
while(!in.hasNextInt()){
System.out.println("Invalid Input");
System.out.println("Insert Number");
in.next();
}
in.nextInt();
}
}

Answer 1

your problem is that you call in.next() inside your while(!in.hasNextInt()).

it´s like you want to eat an apple but there are no apples left.

a possible solution e.g.:
is import java.util.Scanner;

public class Program {

public static void main(String[] args) {
System.out.println("Insert Number");
Scanner in = new Scanner(System.in);
while (in.hasNext()) {
String text = String.valueOf(in.nextInt());
System.err.println(text);
}

}
}