Getting error stating that my if statement is always false, what do i need to do?

So i have been given a task for my degree level programming in Java, the task can be seen below:

My problem is getting errors stating:

• Condition 'a >= 18' is always 'false'

  Condition 'a < 11' is always 'false'

Task

1)In a new command line project, write code which will prompt the
user for the age of a young person (between the age of 11 and 18,
and determine the highest category of film they can view at the
cinema unaccompanied. The categories are PG (any age), 12, 15 and 18

2)Add a default clause stating that they are too young to see a film
unaccompanied.

3)Add an 'if' statement to check if the age entered is over 18. If
so, print a message stating that they can see any film they like,
but if the value is under 18, ensure the switch statement is
executed

My code can be seen below:

package im.ucm.co4025;

import java.util.Scanner;
public class Main {

public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    System.out.println("Please enter your age: ");
    int a = sc.nextInt();
    sc.nextLine();

    switch (a) {
        case 11 -> System.out.println("You can view up to PG rated films unaccompanied");
        case 12, 13, 14 -> System.out.println("You can view films up to a 12 age rating unaccompanied");
        case 15, 16, 17 -> {
            System.out.println("You can view films up to a 15 age rating unaccompanied");


            if (a >= 18) {
                System.out.println("You can watch any film unaccompanied");

            }
            if (a < 11) {
                System.out.println("You are too young to view a film unaccompanied");
            }
        }
    }
    }


}

The following solutions can be provided:

1. if statement to check adult age could be placed outside switch<br/>
   then default in switch is referring to minor ages `[0..10].

if (a >= 18) {
	System.out.println("You can watch any film unaccompanied");
} else {
	switch (a) {
		case 11 -> System.out.println("You can view up to PG rated films unaccompanied");
		case 12, 13, 14 -> System.out.println("You can view films up to a 12 age rating unaccompanied");
		case 15, 16, 17 -> System.out.println("You can view films up to a 15 age rating unaccompanied");
		default -> System.out.println("You are too young to view a film unaccompanied at the age of " + a);
	}
}

2. replace if with a ternary operator in the default:

switch (a) {
	case 11 -> System.out.println("You can view up to PG rated films unaccompanied");
	case 12, 13, 14 -> System.out.println("You can view films up to a 12 age rating unaccompanied");
	case 15, 16, 17 -> System.out.println("You can view films up to a 15 age rating unaccompanied");
	default -> System.out.println(a >= 18 ? 
		"You can watch any film unaccompanied" : 
		"You are too young to view a film unaccompanied at the age of " + a);
}

The reason you're getting this is because the if statements are in the case for 15,16,17.
Thus the only situation where if(a>=18) or if(a<11) is ran the only possible things a could be is 15, 16, or 17.

You have some errors in your code which you must fix.

You can't have if statements in a switch. Better move them outside.

Here's what the working example should be:

import java.util.Scanner; 
public class Main {

public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    System.out.println("Please enter your age: ");
    int a = sc.nextInt();
    if (a >= 18) {
        System.out.println("You can watch any film unaccompanied");

   }else if (a < 11) {
                System.out.println("You are too young to view a film unaccompanied");
            }
    switch (a) {
        case 11:
            System.out.println("You can view up to PG rated films unaccompanied");
            break;
        case 12:
            System.out.println("You can view films up to a 12 age rating unaccompanied");
            break;
        case 13:
            System.out.println("You can view films up to a 12 age rating unaccompanied");
            break;
        case 14:
            System.out.println("You can view films up to a 12 age rating unaccompanied");
            break;
        case 15:
            System.out.println("You can view films up to a 15 age rating unaccompanied");
            break;
        case 16:
            System.out.println("You can view films up to a 12 age rating unaccompanied");
            break;
        case 17:
            System.out.println("You can view films up to a 12 age rating unaccompanied");
            break;

    }
    }


}

Sample I/O

Input

12

Output

You can view films up to a 12 age rating unaccompanied