Print prime numbers
Prime numbers can divisible by 1 and itself
only.
import java.util.Scanner;
public class PrimeNumbers {
public static void main(String[] arg){
int number;
Scanner sc=new Scanner(System.in);
System.out.println("Enter number :");
number=sc.nextInt();
System.out.println("Prime
numbers from 1 to " + number);
for(int i=1;i<=number;i++){
boolean isPrime = true;
//to check it is prime or not
for(int j=2;j<i;j++){
if(i%j==0){
isPrime = false;
break;
}
}
if(isPrime)
System.out.print(i
+ " ");
}
}
}
/*
Output:
Enter number :
20
Prime numbers from 1 to 20
1 2 3 5 7 11 13 17 19
*/