Single digit displaying after entering double digit as input in java Program -

1. in below java code if entering double digit input getting value entered single digit.i think problem & num variable of diff data types. 2.if taking num int value entered converted different value. entered 20 & took 50. please help.

   class primenumber { public static void main(string args[])      throws java.io.ioexception{         system.out.println("enter number test prime number");     char num;     num=(char)system.in.read();     system.out.println("number entered "+num);     boolean tarun =true;             for(int i=2;i<=num/i;i++){                     if(num%i==0){                         tarun=false;                             break;                             }                         }             if(tarun)             system.out.println(num +"  prime number");             else             system.out.println(num +" not prime number ");         }     } 

`output:- enter number test prime number 22 number entered 2 2 not prime number

num=(char)system.in.read(); 

you casting number character? why this?

since num a... number, this:

int num; num = system.in.read();