When to use different types of scanner lines in Java

Question

Hello,

Please take a look at the code below.

Ex.
Line 1:
Scanner scanner = new Scanner(System.in);

Line 2:
// System.out.println(scanner.nextLine());

Lines 3 - 4:
int days = scanner.nextInt();
System.out.println(days);

Lines 5 - 6:
//days = scanner.nextInt();
System.out.println(days*24);

First I set up the scanner, then I can add lines 3, 4 and 6, but if I add line 2 or line 5 I will get Exceptions, and I would like to know why that is not allowed.

Thank you in advance,

Iulia

Answer 1

All lines are valid. They raise exception when you don't provide any corresponding input when the lines expecting inputs..
Line 2: accept a line of string.
Line 3: expects a integer input
Line 5: also accepts an integer input.
so only If the input is not available or mismatch of inputs then it raise exceptions...

Answer 2

Dear @Ę ~ J and @Jayakrishna🇮🇳,

So if I want the scanner to take an input more than once in the program, how can I do that?

Like how would I do it if I wanted to have the same type of input more than once (but the user could put in a different input (of the same type) each time)?

And how can I make it so that I can take in more than one type of input, like Strings and ints?

In that case know I would have to make one scanner for each type of input, but I don't know how I would do that.

Thanks,

Iulia