Java if else in while loop

Question

i had this problem where while looping, the output shows the loop but the invalid is also there. how do i separate the loop and the if...else statements?

below is the program code.

Scanner scan = new Scanner(System.in);
String option = new String("Y");

while (option.equalsIgnoreCase("Y")) {
    System.out.println("Good Morning!!");
    System.out.print("Do you want to continue [Y/N]: ");
    option = scan.nextLine();

    if (option.equalsIgnoreCase("N")) {
        break;

    } else {

        System.out.println("invalid");
    }
}

this is the output of the loop. the invalid is only supposed to show up when i put in a different letter other than y or n

Do you want to continue [Y/N]: y
invalid
Good Morning!!
Do you want to continue [Y/N]: y
invalid
Good Morning!!

and it was supposed to show like this

Good Morning!!
Do you want to continue [Y/N]: y
Good Morning!!
Do you want to continue [Y/N]: y
Good Morning!!
Do you want to continue [Y/N]: n

use continue in else block before System.out.println. docs.oracle.com/javase/tutorial/java/nutsandbolts/branch.html — Milan
– Milan, Commented Oct 31, 2020 at 7:26

David Buck · Accepted Answer · 2020-10-31 10:15:40Z

1

You're just cheking if it's a "N" but not a "Y" so it'll will show invalid for Y. You just have to add another else if and the last else with the invalid.

Scanner scan = new Scanner(System.in);
String option = new String("Y");

while (option.equalsIgnoreCase("Y")) {
    System.out.println("Good Morning!!");
    System.out.print("Do you want to continue [Y/N]: ");
    option = scan.nextLine();

    if (option.equalsIgnoreCase("N")) {
        break;

    }else if(option.equalsIgnoreCase("Y")){
        continue; 
    }else {
        System.out.println("invalid");
   }
}

edited Oct 31, 2020 at 10:15

David Buck

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answered Oct 31, 2020 at 9:24

Tomas Calaf Marti

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Comments

Oleg Cherednik · Accepted Answer · 2020-10-31 06:52:34Z

0

Scanner scan = new Scanner(System.in);

while (true) {
    System.out.println("Good Morning!!");
    System.out.print("Do you want to continue [Y/N]: ");
    String option = scan.nextLine().toUpperCase();

    if ("N".equals(option))
        break;
    if ("Y".equals(option))
        continue;

    System.out.println("invalid");
}

answered Oct 31, 2020 at 6:52

Oleg Cherednik

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1 Comment

corsiKa Over a year ago

This doesn't explain what the changes were and why - it's just a code dumb, which isn't particularly helpful.

Nowhere Man · Accepted Answer · 2020-10-31 08:39:51Z

0

You could also implement else if to check for acceptable character and remove the redundant check from the condition in while:

while (true) {
    System.out.println("Good Morning!!");
    System.out.print("Do you want to continue [Y/N]: ");
    String option = scan.nextLine();

    if (option.equalsIgnoreCase("N")) {
        break;
    } else if (!option.equalsIgnoreCase("Y")) {
        System.out.println("invalid");
    }
}

answered Oct 31, 2020 at 8:39

Nowhere Man

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