can you use length for a boolean

Asked Nov 25 '16 at 02:26

Active Nov 25 '16 at 02:32

Viewed 38 times

I'm trying to get an input(year) from the user and if the user enters four digit input(which is the length) then it will print the year, but if the user enters any other length it will ask again. Why I can't do(year.length ==4); doesn't it means that if the year length is 4 then finish the loop? Thanks

import java.util.Scanner;

public class years {
  public static void main(String[] args) {
    int year;
    Scanner input = new Scanner(System.in);
    do {
      year = input.nextInt();
    }while(year.length == 4);

    System.out.println("Year is " + year);
  }
}

edited Nov 25 '16 at 02:32

asked Nov 25 '16 at 02:26

Vishwajeet Singh

int is a primitive, and you can't call a method or get a property from a primitive. So `year.length` makes no sense at all. – Hovercraft Full Of Eels Nov 25 '16 at 02:29
`year` is a primitive `int`, which has no fields. If you to know if it's 4 digits in length, just check if `year >= 1000 && year <= 9999`. Also, your loop will continue as long as the condition is true, which seems to be the opposite of what you want. – shmosel Nov 25 '16 at 02:34
@HovercraftFullOfEels It makes some sense, it's just incorrect. :) – shmosel Nov 25 '16 at 02:34
@shmosel: not to the Java compiler. ;) – Hovercraft Full Of Eels Nov 25 '16 at 02:35
@shmosel Thanks, now that makes sense, I don't know what I was trying to do. Can you please explain me What does you mean by "year is a primitive int, which has no fields. " Thanks again – Vishwajeet Singh Nov 25 '16 at 02:37
http://stackoverflow.com/questions/10430582/primitive-data-types-in-java – shmosel Nov 25 '16 at 02:42
@shmosel thank you so much – Vishwajeet Singh Nov 25 '16 at 02:48
@shmosel So, there is no way we can use that .length method with a primitive type? Right? But we sometimes use that, don't we? Thanks – Vishwajeet Singh Nov 25 '16 at 02:50
You're probably confusing ints with strings. You can do `String.valueOf(year).length` if you want. – shmosel Nov 25 '16 at 02:51
@shmosel Ah now it makes sense, yeah I was wrong, we can't check the length of an integer because it's just a single value. Right? – Vishwajeet Singh Nov 25 '16 at 02:57

can you use length for a boolean

0 Answers0