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. A prime number is one which is divisible by 1 and itself.

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

public class PrimeNumbersFrom1To100 { public static void main(String[] args) { int maxNumber = 100; boolean prime = true; String primeNumbers = ""; for(int a = 1; a <= maxNumber; a++) { prime =checkPrime(a); if(prime) { primeNumbers = primeNumbers + a + " "; } } System.out.println("Display prime numbers from 1 to " + maxNumber + ": "); System.out.println(primeNumbers); } public static boolean checkPrime(int number) { int remainder; for(int a = 2; a <= number / 2; a++) { remainder = number % a; // if remainder is equal to 0 then number is not prime if(remainder == 0) { return false; } } return true; } }

**Output:**

Display 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

**Java program to display prime numbers from 1 to n**

Similarly we can display prime numbers from 1 to n.

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

Also read – variables in java