OR || not working in while loop when comparing strings

[janey4115]

Hi - the below code is working as exepected - user enter's invalid classification and is advised - user enters correct classification and is advised

import java.util.Scanner;

public class Hello {

	public static void main(String[] args) {
		
		 System.out.print("Please enter classification: ");
		 
		 String classification;
		 
		 Scanner scanner = new Scanner(System.in);

         classification = scanner.nextLine();
       
         while (!"G".equalsIgnoreCase(classification)) 

         {   
            
         System.out.println("Please enter valid classification");    

         classification = scanner.nextLine();
         
         }

output:
Please enter classification: f
Please enter valid classification
G
Valid classification:

However if I try and add an || operator this code no longer works?

import java.util.Scanner;

public class Hello {

	public static void main(String[] args) {
		
		 System.out.print("Please enter classification: ");
		 
		 String classification;
		 
		 Scanner scanner = new Scanner(System.in);

         classification = scanner.nextLine();
       
         while (!"G".equalsIgnoreCase(classification)
               || !"PG".equalsIgnoreCase(classification) ) 

         {   
            
         System.out.println("Please enter valid classification");    

         classification = scanner.nextLine();
         
         }
		
		
         System.out.println("Valid classification: ");


	}

}

Output:
Please enter classification: f
Please enter valid classification
G
Please enter valid classification

Can anyone please advise why?
Thanks
Jane

[NigelRen]

What your trying to do is ask if the text entered is not "G" or it's not "PG" - which will never be true as it can't be both values. Should you be using an and in there( && )?

[Petr]

hi
It does not work because when you enter G the first condition returns false but the second condition returns true and while loop makes a new iteration. You can fix it like this: while (!("G".equals(interUser) || "PG".equals(interUser)))

[janey4115]

Thanks NigelRen - yes && fixed the issue - what a silly mistake

[janey4115]

Thanks Petr