# Java Program to Display Prime Numbers From 1 to N

In this post, we will learn to code the Java Program to Display Prime Numbers From 1 to N. Let’s understand Prime Numbers and How to Check Prime Numbers in Java Programming Language.

In a previous post, we will How to check whether a number is prime or not. Today, we will display all the prime numbers from 1 to N.

Now, let’s see the Java Program to Display Prime Numbers From 1 to N using For Loop.

Contents

## Java Program to Display Prime Numbers From 1 to N

```import java.util.*;

public class Main{

public static boolean isPrime(int number){
if(number == 1) return false;
if (number == 2) {
return true;
}
else {
int count = 0;
//logic
for (int div = 2; div * div <= number ; div++) {
if (number % div == 0) {
count++;
}
}
if(count > 0){
return false;
}
}

return true;
}

public static void main(String[] args){

Scanner sc = new Scanner(System.in);
System.out.println("Enter the value of N :");
int N = sc.nextInt();

System.out.println("All Prime Numbers from 1 to "+N+" are :");
for(int num = 1 ; num <= N ; num++){
if(isPrime(num) == true){
System.out.println(num);
}
}
}

}```

Output 1

``````Enter the value of N : 50

All Prime Numbers from 1 to 50 are :
2
3
5
7
11
13
17
19
23
29
31
37
41
43
47``````

Output 2

``````Enter the value of N : 11

All Prime Numbers from 1 to 11 are :
2
3
5
7
11``````

## How Does This Program Works?

```        Scanner sc = new Scanner(System.in);
System.out.println("Enter the value of N :");
int N = sc.nextInt();```

In this program,we take the input of N from the user using the Scanner Class in Java. Then, we have created a for loop from 1 to N and checked if each number is prime or not and printed each prime number.

```        System.out.println("All Prime Numbers from 1 to "+N+" are :");
for(int num = 1 ; num <= N ; num++){
if(isPrime(num) == true){
System.out.println(num);
}
}```

To understand the optimized way to check prime numbers in Java Programming Language check this, Java Program to Check Prime Number.

This is the Java Program to Print Prime Numbers From 1 to N using for loop.

## Java Program to Print Prime Numbers From 1 to N using While Loop

```import java.util.*;

public class Main{

public static boolean isPrime(int number){
if(number == 1) return false;
if (number == 2) {
return true;
}
else {
int count = 0;
//logic
for (int div = 2; div * div <= number ; div++) {
if (number % div == 0) {
count++;
}
}
if(count > 0){
return false;
}
}

return true;
}

public static void main(String[] args){

Scanner sc = new Scanner(System.in);
System.out.println("Enter the value of N :");
int N = sc.nextInt();

System.out.println("All Prime Numbers from 1 to "+N+" are :");
int num=1;
while(num <= N){
if(isPrime(num) == true){
System.out.println(num);
}
num++;
}
}

}```

Output 1

``````Enter the value of N : 50

All Prime Numbers from 1 to 50 are :
2
3
5
7
11
13
17
19
23
29
31
37
41
43
47``````

Output 2

``````Enter the value of N : 11

All Prime Numbers from 1 to 11 are :
2
3
5
7
11``````

## Conclusion

I hope after going through this post, you understand Java Program to Print Prime Numbers From 1 to N and learned to code a Java Program to Check Prime Number.

If you have any doubt regarding the topic, feel free to contact us in the comment section. We will be delighted to help you.