Java program to display first n prime numbers has been shown here. Here n is a positive integer. For example if n = 5, we get first 5 prime numbers i.e. 2, 3, 5, 7, 11.

#### Page contents:

1. Program & Output

## 1. Java Program & output to display first N prime numbers

Code has been copied
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alphabetacoder.com
Java program to display first N prime numbers
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import java.util.Scanner;
import java.lang.*;

class Main {
// function to check prime
boolean check_prime(int num) {
// declare variables
int i;
// 1 is not prime
if (num == 1)
return false;
// check divisibility of num
for (i = 2; i <= Math.sqrt(num); i++) {
if (num % i == 0) {
return false; // num is composite so return false
}
}
// num is prime so return true
return true;
}

public static void main(String[] args) {
// declare instance of Scanner class
Scanner sc = new Scanner(System.in);
// declare object of class
Main obj = new Main();
// declare variables
int n, num, count;

// take input of the number
System.out.print("Enter the no. of primes = ");
n = sc.nextInt();

// initialize
num = 1;
count = 0;

System.out.print("First " + n + " primes: ");
// find n number of primes
while (count < n) {
// check if current number is prime
if (obj.check_prime(num)) {
System.out.print(" " + num);
count++; // increment counter
}
num++; // increment number
}
}
}

Output

#### Case 1:

Enter the no. of primes = 3

First 3 primes: 2 3 5

#### Case 2:

Enter the no. of primes = 9

First 9 primes: 2 3 5 7 11 13 17 19 23