Java program to display prime numbers from 1 to 100

Let’s learn java program to display prime numbers from 1 to 100.

java program to display prime numbers from 1 to 100

Prime number program in java is most common java interview question.

Java program to display prime numbers from 1 to 100

A prime number is one which is divisible by 1 and itself. Here’s the prime number from 1 to 100 program in java,

Also read – switch statement in java

Here’s the java program to display prime numbers from 1 to 100,

public class PrimeNumbersJava
{
   public static void main(String[] args)
   {
      int a = 0;
      int number = 0;
      String strPrimeNumber = "";
      for(a = 1; a <= 100; a++)
      {
         // prime number program in java
         int counter = 0;
         for(number = a; number >= 1; number--)
         {
            if(a % number == 0)
            {
               counter = counter + 1;
            }
         }
         if(counter == 2)
         {
            strPrimeNumber = strPrimeNumber + a + " ";
         }
      }
      System.out.println("Prime numbers from 1 to 100 : ");
      System.out.println(strPrimeNumber);
   }
}




Output:

Prime numbers from 1 to 100 : 2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59 61 67 71 73 79 83 89 97


Similarly we can display from 1 to n. Here’s the java code for prime number,

import java.util.Scanner;

public class PrimeNumber
{
   public static void main(String[] args)
   {
      Scanner sc = new Scanner(System.in);
      int a = 0;
      int number = 0;
      String strPrimeNumber = "";
      System.out.println("Please enter the value of n : ");
      int n = sc.nextInt();
      for(a = 1; a <= n; a++)
      {
         int count = 0;
         for(number = a; number >= 1; number--)
         {
            if(a % number == 0)
            {
               count = count + 1;
            }
         }
         if(count == 2)
         {
            strPrimeNumber = strPrimeNumber + a + " ";
         }
      }
      System.out.println("Java program to display prime numbers from 1 to n : ");
      System.out.println(strPrimeNumber);
      sc.close();
   }
}




Output:

Please enter the value of n : 200
Java program to display prime numbers from 1 to n :
2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59 61 67 71 73 79 83 89 97 101 103 107 109 113 127 131 137 139 149 151 157 163 167 173 179 181 191 193 197 199


Print using for loop

Let’s learn to print prime numbers from 1 to 100 in java using for loop,

public class PrimeNumberUsingForLoop
{
   public static void main(String[] args) 
   {
      int a, number, counter;
      System.out.println("Prime numbers from 1 to 100 in java using for loop: "); 
      for(number = 1; number <= 100; number++)
      {
         counter = 0;
         for(a = 2; a <= number / 2; a++)
         {
            if(number % a == 0)
            {
               counter++;
               break;
            }
         }
         if(counter == 0 && number != 1)
         {
            System.out.print(number + " ");
         }
      }
   }
}


Output:

Prime numbers from 1 to 100 in java using for loop:
2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59 61 67 71 73 79 83 89 97


Java program to print prime numbers from 1 to 100 using while loop

Here’s the java program to print prime numbers from 1 to 100 using while loop,

public class PrimeNumberUsingWhileLoop
{
   public static void main(String[] args) 
   {
      int a, number = 1, counter;
      System.out.println("Print prime numbers from 1 to 100 using while loop: "); 
      while(number <= 100)
      {
         counter = 0;
         a = 2;
         while(a <= number/2)
         {
            if(number % a == 0)
            {
               counter++;
               break;
            }
            a++;
         }
         if(counter == 0 && number != 1)
         {
            System.out.print(number + " ");
         }
         number++;
      }
   }
}


Output:

Print prime numbers from 1 to 100 using while loop:
2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59 61 67 71 73 79 83 89 97


Also read – java program to print prime numbers in a given range

Also read – print first 10 prime numbers in java

Also read – prime number program in java using scanner