This is because you are using Scanner#next
method. And if you look at the documentation of that method, it returns the next token read.
So, when you read user input using next
method, it does not read the newline
at the end. Which is then read by the nextLine()
inside the while
loop. And thus, your firstName
contains a newline
without you knowing.
So, you should use nextLine()
in your while rather than next()
.
Similar is the case with nextInt
method. It also does not read the newline. So, you can read
using readLine
and convert it to int
using Integer.parseInt
. It can throw NumberFormatException
if input value cannot be converted to int
. So you need to handle it accordingly.
You can try the below code: –
Scanner sc = new Scanner(System.in);
System.out.println("Continue?[Y/N]");
while (sc.hasNext() && (sc.nextLine().equalsIgnoreCase("y"))) {//change here
System.out.println("Enter first name");
String name = sc.nextLine();
System.out.println("Enter surname");
String surname = sc.nextLine();
System.out.println("Enter number");
int number = 0;
try {
number = Integer.parseInt(sc.nextLine());
} catch (IllegalArgumentException e) {
e.printStackTrace();
}
System.out.println("Continue?[Y/N]");
}
But, note one thing, if you enter a value that cannot be passed to Integer.parseInt
you will get an exception, and that input will be skipped. For that case, you need to handle it by using while
loop.
Or, if you don’t want to do that exception handling: –
You can add an empty sc.nextLine()
after sc.nextInt()
, that will consume the newline
left over, like this: –
// Left over part of your while loop
String surname = sc.nextLine();
System.out.println("Enter number");
int number = sc.nextInt();
sc.nextLine(); // To consume the left over newline;
System.out.println("Continue?[Y/N]");