Uncovering the Secrets of Prime Numbers in Java

The Challenge: Checking Prime Numbers in an Interval

Imagine you’re tasked with finding all prime numbers between 0 and 10. Sounds simple, right? But what about the numbers 0 and 1? They’re not prime, so you need to exclude them from your search.

The Power of Loops: A Deeper Look

To tackle this problem, you’ll need to use a combination of while and for loops. The outer while loop will iterate through each number in the interval, while the inner for loop will check whether each number is prime or not. But here’s the catch: you need to reset the value of flag = false on each iteration of the while loop. This ensures that you’re not carrying over any previous results.

The Code: A Step-by-Step Breakdown

public class PrimeNumbers {
    public static void main(String[] args) {
        int lowerBound = 0;
        int upperBound = 10;
        boolean flag;

        while (lowerBound <= upperBound) {
            flag = true;
            for (int i = 2; i <= Math.sqrt(lowerBound); i++) {
                if (lowerBound % i == 0) {
                    flag = false;
                    break;
                }
            }
            if (flag) {
                System.out.print(lowerBound + " ");
            }
            lowerBound++;
        }
    }
}

As you can see, the inner for loop is where the magic happens. It checks each number to see if it’s prime, and if so, adds it to the list. But what about the outer while loop? That’s where the interval comes in.

Understanding the Interval

When checking for prime numbers in an interval, you need to set boundaries. In this case, we’re looking at numbers between 0 and 10. But remember, 0 and 1 aren’t prime, so we need to exclude them. This means our condition will look like this:

while (lowerBound <= upperBound) {
    // code here
}

This ensures that we’re only checking numbers within the specified interval.

Taking it to the Next Level: Functions and More

But what if you want to take your prime number game to the next level? That’s where functions come in. By creating a function to display prime numbers between intervals, you can reuse your code and make it more efficient.

Benefits of using functions:

• Code reusability
• Improved efficiency
• Easier maintenance

Want to learn more about using functions to display prime numbers between intervals? Check out our article on Java Program to Display Prime Numbers Between Intervals Using Function.