TECHNOLOGIES:

# Check A Number is Prime Or Not

Article:
Viewed:  1896
Posted On:  23/07/2013 12:23:16
In this article i am going to show you how we can check the number given by user is prime or not.........

Below is my code:

import java.util.Scanner;

class prime
{
public static void main(String s[]){
int a,b;
System.out.println("enter no. to check prime");
Scanner scan=new Scanner(System.in);
a=scan.nextInt();

System.out.println("you entered "+a);

for(b=2;b<=a-1;b++)
{
if(a%b==0)
{
System.out.println("no. is not prime");
break;
}
}

if(a==b)
{
System.out.print("prime");}
}
}

Step 1:  After writing this in notepad save the file with the name followed by (.java) for eg: I saved it with Prime.java

Step 2 :
Open command prompt

Step 3 : Write javac Prime.java - Press Enter for compilation

Step 4 : Write java Prime for execution

Output:

Image 1.

 Comment:
By Umesh  On  20/10/2014 03:27:26
Hello Good Article You can increase performance check number upto num/2 .. then it will reduce time complexity by half time. for(b=2;b<=a/2;b++) { if(a%b==0) { System.out.println("no. is not prime"); break; } } Thanks Umesh Happy Coding