Count the prime number in a certain range in Java

 

In Java, counting prime numbers within a specific range can be accomplished using various techniques. One common approach is to iterate through the numbers in the range and check if each number is prime. By implementing this iterative method, you can efficiently determine the total count of prime numbers within the given range.

Count the prime number in a certain range

 

public class PrimeNumberCounter {
    public static void main(String[] args) {
        int lowerBound = 1;
        int upperBound = 100;
        int count = 0;

        for (int number = lowerBound; number <= upperBound; number++) {
            if (isPrime(number)) {
                count++;
            }
        }

        System.out.println("The number of prime numbers in the range [" + lowerBound + ", " + upperBound + "] is: " + count);
    }

    public static boolean isPrime(int number) {
        if (number <= 1) {
            return false;
        }

        for (int i = 2; i <= Math.sqrt(number); i++) {
            if (number % i == 0) {
                return false;
            }
        }

        return true;
    }
}

OUTPUT:

The number of prime numbers in the range [1, 100] is: 25