Summary: In this programming example, we will learn to print the nth prime number using the Java language.

A Prime number is a number that is only divisible by 1 and itself. For example: 5, 7, 11, etc.

To print the nth prime number, we keep searching for the next prime number starting from 1 until we reach the nth prime number.

For this, we keep counting the prime numbers and when we reach the nth prime number, we output the same.

``````import java.util.Scanner;

public class NthPrime {
public static void main(String args[]){
Scanner in = new Scanner(System.in);

int i=1, n, c =0;

System.out.print("Enter the value of n: ");
n= in.nextInt();

//While loop should run until we get to the nth prime number
while(c!=n){
i++;
if(isPrime(i))
c++;  //'c' will get incremented every time when we find a prime number
}

System.out.println("Nth Prime Number is: "+i);
}

private static boolean isPrime(int num){
boolean flag = true;
for(int i=2; i<num; i++){
if(num%i == 0){
/*
*If num is divisible by any number other than 1 and itself
*then, it is Not Prime.
*/
flag = false;
break;
}
}
return flag;
}
}``````

Output:

Enter the value of n: 15
Nth Prime Number is: 47

In this Java program, we ask the user to input the value of n.

After the user enters n, using while loop we search the next prime number until `c=n`.

The variable `c` in the above program is keeping the count of the prime numbers found till then.