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Java program for Prime Number | Check whether Number is Prime or Not
Check Prime Number Example in Java - This program will read an integer number and check whether given number is Prime or Not, in this program we will divide number from 2 to number/2, if number divide by any number then number will not be prime number.
Check Prime Number using Java Program
//Java program for Prime Number
import java.util.*;
public class Prime
{
public static void main(String args[]){
int num,loop;
boolean flag=false;
Scanner bf=new Scanner(System.in);
//input an integer number
System.out.print("Enter any integer number: ");
num= bf.nextInt();
//check prime
for(loop=2; loop<=(num/2); loop++)
{
if(num%loop==0)
{
flag=true;
break;
}
}
if(flag==false)
System.out.println(num + " is a prime number.");
else
System.out.println(num + " is not a prime number.");
}
}
Output
me@linux:~$ javac Prime.java
me@linux:~$ java Prime
Enter any integer number: 79
79 is a prime number.
Using function/Method
//Java program for Prime Number
import java.util.*;
public class Prime
{
//function to check number is prime or not
public static boolean isPrime(int num)
{
//check prime
for(int loop=2; loop<=(num/2); loop++)
{
if(num%loop==0)
return false;
}
return true;
}
public static void main(String args[]){
int num,loop;
boolean flag=false;
Scanner bf=new Scanner(System.in);
//input an integer number
System.out.print("Enter any integer number: ");
num= bf.nextInt();
if(isPrime(num))
System.out.println(num + " is a prime number.");
else
System.out.println(num + " is not a prime number.");
}
}
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