Question

Write a program in java to check prime numbers

Answer 1

hola

TO check it following is program to check whether a number is a prime or not

public class PrimeExample{  
   public static void main(String args[]){   
   int i,m=0,flag=0;     
   int n=3;//it is the number to be checked 
     m=n/2;   
     if(n==0||n==1){  
   System.out.println(n+" is not prime number");  
      }else{ 
    for(i=2;i<=m;i++){
          if(n%i==0){       
    System.out.println(n+" is not prime number"); 
          flag=1;         
  break;          }         }        
 if(flag==0)  { System.out.println(n+" is prime number"); }
    }//end of else  
}   
 }   

Answer 2

// This program is to check whether the given number is prime number or not
class Prime_number
{
public void main(int n)
{
int i, c=0;
for (i=1;i<=n;i++)
{
if (i%n == 0)
c++;
}
if (c==2)
{
System.out.println("The given number is a prime number");
}
else
{
System.out.println("The given number is not a prime number");
}
}
}

Here
Variable n : to take a number from user
              i  : for increment
              c : to count how many times it is equal to zero