Given a list of integers, how can you check whether it contains at least one prime number using Java 8 Streams?
Example :
import java.util.Arrays;
import java.util.List;
public class PrimeCheck {
public static void main(String[] args) {
// Input parameter as "Java Knowledge Base"
List<Integer> numbers = Arrays.asList(4, 54, 2, 6, 15, 16);
boolean containsPrimeNumber = numbers.stream()
.anyMatch(PrimeCheck::isPrime);
System.out.println("ArrayList contains prime numbers: " + containsPrimeNumber);
}
public static boolean isPrime(int num) {
if (num <= 1) return false;
for (int i = 2; i <= Math.sqrt(num); i++) {
if (num % i == 0) return false;
}
return true;
}
}
✅ Explanation:
- We define a
List<Integer> numberswith values[4, 54, 2, 6, 15, 16]. - We use Java 8 Stream API:
numbers.stream().anyMatch(PrimeCheck::isPrime);.stream()converts the list to a stream..anyMatch(PrimeCheck::isPrime)checks if any number in the list is prime by calling theisPrime()method.
- The method
isPrime(int num)efficiently checks for primality by iterating up to the square root of the number.
✅ Expected Output:
ArrayList contains prime numbers: true
✅ Why Output is true:
- The number
2is prime, so.anyMatch()returnstrue.
