Simple Program for Prime Number

simple program to print prime number in java & c++/c#.

Simple java Program to print prime numbers 

  To find Prime Number or Not  in java

public class primenum {
public void pri()  {
int num = 1 ;
int i;
int count=0;

while(num<100)
{
for(i=1;i<=num;i++)   {
if(num%i==0)  {
count++;
}}
if(count==2){
System.out.println("prime"+num);
count=0;
num++;
}
else {
count = 0;
num++;
}
}}

public static void main(){
primenum p1 = new primenum;
p1.pri();
}
}

   This program print 1st 100 prime numbers


      The Prime Number has no divisor other than 1 & itself .From the following  code when count becomes 2 (i.e count=2 ) it is a prime number i.e 'if(num%i==0)'  condition is satisfied two times, when the number is divided by 1 & itself.
         

              if(num%i==0)  {
              count++;
                  }

Output:
     2
     3
     5
     7
     11 .......
   

To run this code :
     1. Save the code as 'primenum.java'
     2. Compile the primenum.java using below command.
             javac primenum.java
     3. Run the code
             java primenum

Above method is to run the code in the command prompt or terminal. You can also run it in IDE.