Print prime numbers from 1 to 100 in java

In this program, we will print prime numbers from 1 to 100 in java.

A prime number is a number which has only two divisors 1 and itself. To check if the number is prime or not, we need to see if it has any other factors other than 1 or itself. If it has, then number is not prime else number is prime.

Algorithm

• Iterate from 1 to 100.
• In each iteration, check is number is prime or not.
• If number is not divisible from 1 to sqrt(n) then number is not prime.
• If number is prime, print it.

Here is java program to print prime numbers from 1 to 100.

package org.arpit.java2blog;

public class PrintPrimeNumberMain {

    public static void main(String[] args) {
        System.out.println("Prime numbers between 1 to 100 are:");
        for (int i = 1; i < 100; i++) {
            if(isPrimeNumber(i))
            {
                System.out.print(" "+i);
            }
        }
    }

    public static boolean isPrimeNumber(int number) {
           if (number <= 1) {
               return false;
           }
           for (int i = 2; i <= Math.sqrt(number); i++) {
               if (number % i == 0) {
                   return false;
               }
           }
           return true;
    }
}

When you will run above program, you will get below output:

That’s all about print prime numbers from 1 to 100 in java.