Welcome back!

I'm currently learning Java, so this exercise is from the course I'm taking. This one is simple, but I thought it was worth writing about since I'm learning a new language!

The Challenge

We have a dog that likes to bark. We need to wake up if the dog is barking at night!

Write a method shouldWakeUp that has 2 parameters:

• barking of type boolean, representing whether our dog is currently barking
• hourOfDay of type int and has a valid range of 0-23

We have to wake up if the dog is barking before 8 or after 22 hours so in that case return true.

In all other cases return false.

If the hourOfDay parameter is less than 0 or greater than 23 return false.

Examples of input and output

public class BarkingDog {
    public static void main(String[] args) {
        System.out.println(shouldWakeUp(true, 1));
        // returns true since the dog is barking during sleeping hours

        System.out.println(shouldWakeUp(false, 2));
        // returns false since the dog is not barking

        System.out.println(shouldWakeUp(true, 8));
        // returns false, since it's not before 8

        System.out.println(shouldWakeUp(true, -1));
        // returns false since the hourOfDay parameter needs to be in a range of 0-23
    }

    // shouldWakeUp method
}

STOP READING if you want to try this on your own!

My Solution

public class BarkingDog {
    public static void main(String[] args) {
        System.out.println(shouldWakeUp(true, 1)); // returns true
        System.out.println(shouldWakeUp(false, 2)); // returns false
        System.out.println(shouldWakeUp(true, 8)); // returns false
        System.out.println(shouldWakeUp(true, -1)); // returns false
    }

    public static boolean shouldWakeUp(boolean barking, int hourOfDay) {
        boolean sleepingHours = (hourOfDay >= 0 && hourOfDay < 8) || hourOfDay == 23;

        return barking && sleepingHours;
    }
}

Sleeping Hours

This was tricky.

I was going to use multiple if-else statements but I thought it was simpler to make a boolean variable called sleepingHours.

The sleeping hours are from >= 11:00 PM (23) and < 8:00 AM (8). You just have to keep in mind that the hour resets to 0 after the 23rd hour with military time.

The variable sleepingHours holds the boolean value of the expression:

boolean sleepingHours = (hourOfDay >= 0 && hourOfDay < 8) || hourOfDay == 23;

The logical OR operator || evaluates whether hourOfDay is either:

• greater than or equal to 0 AND less than 8
• equal to 23.

sleepingHours will be true if one of those conditions is met.

The expression also validates whether hourOfDay is within 0-23 because it will return false if it isn't.

Return Statement

return barking && sleepingHours;

The return statement is a boolean expression with barking and sleepingHours. The method shouldWakeUp will return true only if both are true, otherwise it will return false.

It's Your Turn

I hope you had fun with this!

Here are some questions for you:

• Did you do this differently?
• Are you learning any new languages?
• Which programming language is your favorite?

Let me know in the comments!